Articles

204 documents.
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Turiel A., M. Piles, V. González-Gambau, J. Ballabrera-Poy, C. Gabarró, J. Martínez, E. Olmedo, M. Portabella, F. Pérez, J. Solé
Scientia Marina, 80S1, 173-193. DOI: 10.3989/scimar.04291.15A (BibTeX: turiel.etal.2016h)
Resum: Veure
Summary: Soil Moisture and Ocean Salinity (SMOS) is the first satellite mission capable of measuring sea surface salinity and soil moisture from space. Its novel instrument (the L-band radiometer MIRAS) has required the development of new algorithms to process SMOS data, a challenging task due to many processing issues and the difficulties inherent in a new technology. In the wake of SMOS, a new community of users has grown, requesting new products and applications, and extending the interest in this novel brand of satellite services. This paper reviews the role played by the Barcelona Expert Centre under the direction of Jordi Font, SMOS co-principal investigator. The main scientific activities and achievements and the future directions are discussed, highlighting the importance of the oceanographic applications of the mission.
Paraules clau: SMOS; salinity; ocean circulation; oceanography; soil moisture; sea ice; radiometry; remote sensing
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Bernardello R., E. Serrano, R. Coma, M. Ribes, N. Bahamon
Marine Ecology Progress Series, 559, 21-34. DOI: 10.3354/meps11896 (BibTeX: bernardello.etal.2016)
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Aymerich I.F.,
PhD thesis. Director/es: J. Piera; A.M. Sánchez. (BibTeX: aymerich.2016d)
Resum: Veure
There is a lack on ocean dynamics understanding, and that lead oceanographers to the need of acquiring more reliable data to study ocean characteristics. Oceanographic measurements are difficult and expensive but essential for effective study oceanic and atmospheric systems. Despite rapid advances in ocean sampling capabilities, the number of disciplinary variables that are necessary to solve oceanographic problems is large. In addition, the time scales of important processes span over ten orders of magnitude, and due to technology limitations, there are important spectral gaps in the sampling methods obtained in the last decades. Thus, the main limitation to understand these dynamics is an inaccurate measurement of the process due to undersampling. But fortunately, recent advances in ocean platforms and in situ autonomous sampling systems and satellite sensors are enabling unprecedented rates of data acquisition as well as the expansion of temporal and spatial coverage. Many advances in technologies involving different areas such as computing, nanotechnology, robotics, molecular biology, etc. are being developed. There exist the effort that these advantages could be applied to ocean sciences and will prove to extremely beneficial for oceanographers in the next few decades. Autonomous underwater vehicles, in situ automatic sampling devices, high spectral resolution optical and chemical sensors are some of the new advances that are being utilized by a limited number of oceanographers, and in a few years are expected to be widely used. Thanks to new technologies and, for instance, utilization of data assimilation models coupled with autonomous sampling platforms can increase temporal and spatial sampling capabilities. For instance, studies of phytoplankton dynamics in the water column, or the transportation and aggregation of organisms need a high rate of sampling because of their rapid evolution, that is why new strategies and technologies to increase sampling rate and coverage would be really useful. However, other challenges come up when increasing the variety and quantity of ocean measurements. For instance, number of measurements are limited by costs of instruments and their deployment, as well as data processing and production of useful data products and visualizations. In some studies, there exists the necessity to discriminate and detect different phytoplankton species present in sea water, and even track their evolution. The use of their optical properties is one of the approximations used by some of them. Acquiring optical properties is a non-invasive and non-destructive method to study phytoplankton communities. Phytoplankton species are then organized thanks to presenting similar optical characteristics. Fluorescence spectroscopy has been used and found as a really potential technique for this goal, although passive optical techniques such as the study of the absorption can be also useful, or even their combination can be studied. Specifically speaking about fluorescence, the majority of the studies have centered their effort in discriminating phytoplankton groups using their excitation spectra because the emission spectra contains less information. The inconvenient of using this kind of information, is that the acquisition is not instantaneous and it is necessary to spend some time (over a second) exciting the sample at different wavelengths sequentially. In contrast, the whole emission spectra can be acquired instantaneously. Therefore, the aim of this thesis is to explore new and powerful signal processing techniques able to discriminate between different phytoplankton groups from their emission fluorescence spectra. This document presents important results that demonstrate the capabilities of these methods.
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G.L. Hunt Jr., K.F. Drinkwater, K. Arrigo, J. Berge, K.L. Daly, S. Danielson, M. Daase, H. Hop, E. Isla, N. Karnovsky, K. Laidre, F.J. Mueter, E.J. Murphy, P.E. Renaud, W.O. Smith Jr., P. Trathan, J. Turner, D. Wolf-Gladrow
Progress in Oceanography, 149, 40-81. DOI: 10.1016/j.pocean.2016.10.004 (BibTeX: huntjr..etal.2016b)
Resum: Veure
We compare and contrast the ecological impacts of atmospheric and oceanic circulation patterns on polar and sub-polar marine ecosystems. Circulation patterns differ strikingly between the north and south. Meridional circulation in the north provides connections between the sub-Arctic and Arctic despite the presence of encircling continental landmasses, whereas annular circulation patterns in the south tend to isolate Antarctic surface waters from those in the north. These differences influence fundamental aspects of the polar ecosystems from the amount, thickness and duration of sea ice, to the types of organisms, and the ecology of zooplankton, fish, seabirds and marine mammals. Meridional flows in both the North Pacific and the North Atlantic oceans transport heat, nutrients, and plankton northward into the Chukchi Sea, the Barents Sea, and the seas off the west coast of Greenland. In the North Atlantic, the advected heat warms the waters of the southern Barents Sea and, with advected nutrients and plankton, supports immense biomasses of fish, seabirds and marine mammals. On the Pacific side of the Arctic, cold waters flowing northward across the northern Bering and Chukchi seas during winter and spring limit the ability of boreal fish species to take advantage of high seasonal production there. Southward flow of cold Arctic waters into sub-Arctic regions of the North Atlantic occurs mainly through Fram Strait with less through the Barents Sea and the Canadian Archipelago. In the Pacific, the transport of Arctic waters and plankton southward through Bering Strait is minimal. In the Southern Ocean, the Antarctic Circumpolar Current and its associated fronts are barriers to the southward dispersal of plankton and pelagic fishes from sub-Antarctic waters, with the consequent evolution of Antarctic zooplankton and fish species largely occurring in isolation from those to the north. The Antarctic Circumpolar Current also disperses biota throughout the Southern Ocean, and as a result, the biota tends to be similar within a given broad latitudinal band. South of the Southern Boundary of the ACC, there is a large-scale divergence that brings nutrient-rich water to the surface. This divergence, along with more localized upwelling regions and deep vertical convection in winter, generates elevated nutrient levels throughout the Antarctic at the end of austral winter. However, such elevated nutrient levels do not support elevated phytoplankton productivity through the entire Southern Ocean, as iron concentrations are rapidly removed to limiting levels by spring blooms in deep waters. However, coastal regions, with the upward mixing of iron, maintain greatly enhanced rates of production, especially in coastal polynyas. In these coastal areas, elevated primary production supports large biomasses of zooplankton, fish, seabirds, and mammals. As climate warming affects these advective processes and their heat content, there will likely be major changes in the distribution and abundance of polar biota, in particular the biota dependent on sea ice.
Paraules clau: Advection, Climate change, Polar and sub-polar biota, Polar marine ecosystems, Sea ice
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Sánchez-Pérez E.D., I. Marín, S. Nunes, F.L. Aparicio, L. Fernández-González, F. Peters, M. Pujo-Pay, P. Conan, C. Marrasé
Scientia Marina, 80, 4, 437-446. DOI: 10.3989/scimar.04318.20B (BibTeX: sanchezperez.etal.2016a)
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Alacid E., M.G. Park, M. Turon, K. Petrou, E. Garcés
Frontiers in Microbiology, 7, 769, 1-13. DOI: 10.3389/fmicb.2016.00769 (BibTeX: alacid.etal.2016a)
Resum: Veure
Marine microbial interactions involving eukaryotes and their parasites play an important role in shaping the structure of phytoplankton communities. These interactions may alter population densities of the main host, which in turn may have consequences for the other concurrent species. The effect generalist parasitoids exert on a community is strongly dependent on the degree of host specificity. Parvilucifera sinerae is a generalist parasitoid able to infect a wide range of dinoflagellates, including toxic-bloom-forming species. A density-dependent chemical cue has been identified as the trigger for the activation of the infective stage. Together these traits make Parvilucifera-dinoflagellate hosts a good model to investigate the degree of specificity of a generalist parasitoid, and the potential effects that it could have at the community level. Here, we present for the first time, the strategy by which a generalist dinoflagellate parasitoid seeks out its host and determine whether it exhibits host preferences, highlighting key factors in determining infection. Our results demonstrate that in its infective stage, P. sinerae is able to sense potential hosts, but does not actively select among them. Instead, the parasitoids contact the host at random, governed by the encounter probability rate and once encountered, the chance to penetrate inside the host cell and develop the infection strongly depends on the degree of host susceptibility. As such, their strategy for persistence is more of a game of Russian roulette, where the chance of survival is dependent on the susceptibility of the host. Our study identifies P. sinerae as a potential key player in community ecology, where in mixed dinoflagellate communities consisting of hosts that are highly susceptible to infection, parasitoid preferences may mediate coexistence between host species, reducing the dominance of the superior competitor. Alternatively, it may increase competition, leading to species exclusion. If, however, highly susceptible hosts are absent from the community, the parasitoid population could suffer a dilution effect maintaining a lower parasitoid density. Therefore, both host community structure and host susceptibility will determine infectivity in the field.
Paraules clau: Parvilucifera, dinoflagellates, perkinsids, host–parasite interactions, specificity, prevalence
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Barbosa A., V. Balagué, F. Valera, A. Martínez, J. Benzai, M. Motas, J.I. Díaz, C. Pedrós-Alió
Plos One. Open acces, 11, 4, 1-14. DOI: 10.1371/journal.pone.0153215 (BibTeX: barbosa.etal.2016)
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Berdalet E., D. Blasco, D. Vaqué
Scientia Marina, 80, S1, 11-14. DOI: 10.3989/scimar.04529.06A (BibTeX: berdalet.etal.2016c)
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Ptacnik R., A. Gomes, S.-J. Royer, S. A. Berger , A. Calbet, J. C. Nejstgaard, J. M. Gasol, S. Isari, S. D. Moorthi, R. Ptacnikova, M. Striebel, A. F. Sazhin, T. M. Tsagaraki, S. Zervoudaki, K. Altoja, P. D. Dimitriou, P. Laas, A. Gazihan, R. A. Martínez, S. Schabhüttl, I. Santi, D. Sousoni, P. Pitta
Scientific Reports, 6, 29286, 1-10. DOI: 10.1038/srep29286 (BibTeX: ptacnik.etal.2016)
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Conti D., A. Orfila, E. Mason, J.M. Sayol, G. Simarro, S. Balle
Ocean Dynamics, 66, 11, DOI: 10.1007/s10236-016-0990-7 (BibTeX: conti.etal.2016c)
Resum: Veure
This work introduces a new method for ocean eddy detection that applies concepts from stationary dynamical systems theory. The method is composed of three steps: first, the centers of eddies are obtained from fixed points and their linear stability analysis; second, the size of the eddies is estimated from the vorticity between the eddy center and its neighboring fixed points, and, third, a tracking algorithm connects the different time frames. The tracking algorithm has been designed to avoid mismatching connections between eddies at different frames. Eddies are detected for the period between 1992 and 2012 using geostrophic velocities derived from AVISO altimetry and a new database is provided for the global ocean.
Paraules clau: Coherent structures, Global ocean, Mesoscale eddies, Dynamical systems theory, Stability analysis of fixed points, Tracking algorithm
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Sánchez N., A. González-Zamora, M. Piles, J. Martínez-Fernández
Remote Sensing, 8, 4, 287. DOI: 10.3390/rs8040287 (BibTeX: sanchez.etal.2016b)
Resum: Veure
A new index for agricultural drought monitoring is presented based on the integration of different soil/vegetation remote sensing observations. The synergistic fusion of the surface soil moisture (SSM) from the Soil Moisture and Ocean Salinity (SMOS) mission, with the Moderate Resolution Imaging Spectroradiometer (MODIS) derived land surface temperature (LST), and water/vegetation indices for agricultural drought monitoring was tested. The rationale of the approach is based on the inverse relationship between LST, vegetation condition and soil moisture content. Thus, the proposed Soil Moisture Agricultural Drought Index (SMADI) combines the soil and temperature conditions while including the lagged response of vegetation. SMADI was retrieved every eight days at 500 m spatial resolution for the whole Iberian Peninsula (IP) from 2010 to 2014, and a time lag of eight days was used to account for the plant response to the varying soil/climatic conditions. The results of SMADI compared well with other agricultural indices in a semiarid area in the Duero basin, in Spain, and also with a climatic index in areas of the Iberian Peninsula under contrasted climatic conditions. Based on a standard classification of drought severity, the proposed index allowed for a coherent description of the drought conditions of the IP during the study period.
Paraules clau: drought; MODIS; SMOS; LST; NDVI; soil moisture; agriculture
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Lin W., M. Portabella, A. Turiel, A. Stoffelen, A. Verhoef
IEEE Transactions on Geoscience and Remote Sensing, 54, 7, 3890-3898. DOI: 10.1109/TGRS.2016.2529700 (BibTeX: lin.etal.2016l)
Resum: Veure
Singularity analysis has proven to be a complementary tool to the Advanced Scatterometer (ASCAT) inversion residual (or maximum likelihood estimator) in terms of wind quality control (QC). In this paper, a new implementation scheme of singularity exponent (SE) is developed for ASCAT data analysis. It combines the wavelet projections of the gradient measurements of multiple parameters into the analysis, ensuring that the analyzed parameters contribute equally to the final singularity map. Therefore, the underlying geophysical phenomena in the different ASCAT-derived parameters can be effectively revealed simultaneously on a unique map of SEs. The validation using both buoy winds and European Centre for Medium-Range Weather Forecasting forecast wind output shows that the newly derived SE significantly improves the current ASCAT wind QC. In particular, poor-quality ASCAT measurements at low-wind and high-variability conditions (w < 4 text{m/s}) can be effectively screened using the new SE.
Paraules clau: Advanced Scatterometer (ASCAT), maximum likelihood estimator (MLE), quality control (QC), singularity vanalysis (SA), wind variability
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Movilla J., E. Calvo, R. Coma, E. Serrano, A. López-Sanz, C. Pelejero
Marine Biology, 163, 6, 1-14. DOI: 10.1007/s00227-016-2908-9 (BibTeX: movilla.etal.2016)
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Gutt J., V. Cummings, P. Dayton, E. Isla, A. Jentsch, S. Schiaparelli
In: Marine Animal Forests : The Ecology of Benthic Biodiversity Hotspots, Ed. S. Rossi, L. Bramanti, A. Gori, C. Orejas Saco del Valle. Springer. 1-30. DOI: 10.1007/978-3-319-17001-5_8-1 ISBN: 978-3-319-17001-5 (BibTeX: gutt.etal.2016a)
Resum: Veure
Both Southern Ocean and terrestrial systems contain three-dimensional biotic components that are key in shaping and defining their respective ecosystems and communities. Antarctic suspension-feeding communities, which inhabit the shelf of the Southern Ocean, resemble “Terrestrial Vegetation Forests” (TVF) or shrublands and support the concept of “Antarctic Marine Animal Forests” (AMAF). They comprise mostly sessile animals, provide microniches for an associated mobile fauna, and are fragmented and regionally mixed with other communities. On land, only high mountains and very dry regions are unsuitable for TVF, analogous to the virtual absence of AMAF from the deep sea (>1000 m). Besides fundamental differences between these systems in energy flow and other ecological drivers such as light requirements and dispersal opportunities, both “forests” experience similar disturbances, which impact ecosystem dynamics and diversity in similar ways. While land use affects and reduces terrestrial forests, climate change and fishing impacts are the most serious threats to the Southern Ocean ecosystem. Research priorities for a better understanding of “Antarctic Marine Animal Forests” demand (1) mapping biotic communities and their structural and functional diversity, especially in terms of hot and cold spots; (2) understanding ecological function, including ecosystem productivity and dynamics; (3) cross-system comparison to identify generality or uniqueness in ecosystem structure and dynamics; and (4) implication of existing and new research approaches and conservation strategies.
Paraules clau: Limiting factors, ecological drivers, areal coverage, three-dimensional structure, interactions, energy, flow, disturbance, climate change, conservation
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Marín I., S. Nunes, E.D. Sánchez-Pérez, F.L. Aparicio, M. Estrada, C. Marrasé, T. Moreno, T. Wagener, X. Querol, F. Peters
Science of The Total Environment, 574, 553-568. DOI: 10.1016/j.scitotenv.2016.09.005 (BibTeX: marin.etal.2016a)
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Lang S., W. Lin, Q. Bao, Y. Zhang
Remote Sensing Technology and Application, 31, 6, 1069-1074. DOI: 10.11873/j.issn.1004-0323.2016.6.1069 (BibTeX: lang.etal.2016a)
Resum: Veure
Wave numerical simulations of East China Sea,Eastern Pacific and central Pacific waters near Hawaii are carried out based on third-generation wave model WAVEWATCH Ⅲ,using NCEP/QuikSCAT wind field as model mixed input.In East China Sea,it is obtained that significant wave height and the reference value of buoy has a strong correlation coefficient,and the root mean square error of wave height is about 0.5 m by simulation;In the Pacific waters near the east coast and Hawaii,significant wave height values are generally lower than the reference value of buoy,root mean square error of wave height of different months is between 0.4 and 1.2 m,but the simulation of wave height and the reference value of buoy still has strong correlation.The results show that it is feasible that taking advantage of WAVEWATCH Ⅲ combined NCEP/QuikSCAT mixed wind field to simulate the wave height of East China Sea.However,it is still necessary to consider some non-wind factors in simulation of wave height lies at Pacific Ocean and the eastern open deep waters.
Paraules clau: WAVEWATCH Ⅲ NCEP/QuikSCAT mixed wind field Significant wave height Buoy
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Viúdez Á., M. Fernández-Pedrera, R. Rodríguez-Marroyo
Scientia Marina, 80S1, 235-248. DOI: 10.3989/scimar.04297.06B (BibTeX: viudez.etal.2016a)
Resum: Veure
Offshore wind is proposed as an energy source to upwell nutrient-rich deep water to the ocean photic layers. A spar-buoy wind turbine with a rigid tube about 300 m long is proposed as a pipe to drive deep water up to the surface. The minimum energy required to uplift the water is the potential energy difference between surface waters inside and outside the pipe, which depends on the background density profile. The corresponding surface jump or hydraulic head, h, calculated for several analytical and experimental density profiles, is of the order of 10 cm. If the complete turbine power (of the order of several MW) is used for raising the water (assuming a 100% pump efficiency), in a frictionless flow, very large water volumes, of the order of thousands of m3 s−1, will be transported to the photic layers. In a more realistic case, taking into account pipe friction in wide pipes, of the order of 10 m radius, and a power delivered to the fluid of 1 MW, the volume transport is still very large, about 500 m3 s−1. However, such a large amount of dense water could sink fast to aphotic layers due to vertical static instability (the fountain effect), ruining the enhancement of primary production. Hence, some ways to increase the turbulent entrainment and avoid the fountain effect are proposed. From the energetic viewpoint, artificial upwelling using offshore wind energy is a promising way to fertilize large open sea regions. This mariculture application is, however, severely subjected to atmosphere and ocean climatology, as well as to ecological dynamics. The general problem is multidisciplinary, and some important physical, engineering and ecological questions need to be seriously addressed to improve our confidence in the approach presented here.
Paraules clau: artificial upwelling; mariculture applications; ocean fertilization; offshore wind energy; spar-buoy wind turbine.
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Muntadas A., S. de Juan, M. Demestre
Ecological Indicators, 61, Part 2, 882-892. DOI: 10.1016/j.ecolind.2015.10.041 (BibTeX: muntadas.etal.2016b)
Resum: Veure
Fishing disturbance on ecosystems leads to changes in community structure and composition, which may have drastic implications for ecosystem functional performance. Functional redundancy, defined as species sharing similar functional roles, is a community property that plays an important role in preventing functional changes in ecosystems under pressure. In this study, we suggest that functional redundancy may be achieved through trait abundance (i.e. large amounts of a trait, hereafter “common traits”), or through trait richness (i.e. large numbers of distinct taxa exhibiting the same trait, hereafter “widespread traits”). We assessed the variability of both measures obtained from epifaunal and infaunal communities in soft-bottom trawling grounds. Sampling sites were located in four Mediterranean areas that were subjected to different levels of trawling effort. Common and widespread traits measures were based on the analysis of biological traits linked to key soft-bottoms functions such as nutrient cycling, bentho-pelagic coupling and habitat provision. The role of rare species in both measures was also assessed and we observed that, in our study sites, rare species generally exhibited the same traits as the most abundant species. Common and widespread traits measures provided complementary information on benthic functional redundancy. Thus, we suggest that a combination of the two measures should be used to appropriately assess benthic functional redundancy in trawling grounds. As redundancy is a component of ecosystem resilience, functional redundancy evaluation is important to assess the overall integrity of ecosystems.
Paraules clau: Biological trait analysis, trawling, benthic infauna and epifauna, resilience, soft-bottoms, Mediterranean
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Griego G., W. Lin, M. Migliaccio, M. Portabella
Proceedings International Geoscience and Remote Sensing Symposium (IGARSS), Beijing, China, 11-15 July, 2016., . (BibTeX: griego.etal.2016c)
Resum: Veure
The empirical dependence of the azimuth wavelength cut-off on the significant wave height and on the wind speed have been studied. The azimuth cut-off is estimated on the fitting of a Gaussian function to the azimuth autocorrelation function of the radar cross section. The feasibility of estimating the significant wave height and/or the wind speed has been investigated as well. We use SAR images acquired by the European Sentinel 1 from the beginning of November 2014 to the end of April 2015 co-located with the scatterometer winds acquired by the Chinese sensor HSCAT and the significant wave height from ECMWF forecasts. The correlation between the azimuth cut-off and the significant wave height is rather strong. A linear geophysical model function is fitted in order to estimate it. The dependence on the wind speed is secondary and becomes remarkable only when the sea state is fully developed. A significant wave height retrieval exercise is proposed and the results are compared with the buoy measurements of the National Data Buoy Center (NDBC) network
Paraules clau: SAR, significant wave height, Sentinel 1
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Povea P., I. Cacho, A. Moreno, L.D. Pena, M. Menéndez, E. Calvo, M. Canals , R.S. Robinson, F.J. Méndez, J.-A. Flores
Paleoceanography, 31, 5, 522-538. DOI: 10.1002/2015PA002883 (BibTeX: povea.etal.2016a)
Resum: Veure
Here we present a new set of high-resolution early Pleistocene records from the eastern equatorial Pacific (EEP). Sediment composition from Ocean Drilling Program Sites 1240 and 1238 is used to reconstruct past changes in the atmosphere-ocean system. Particularly remarkable is the presence of laminated diatom oozes (LDOs) during glacial periods between 1.85 and 2.25 Ma coinciding with high fluxes of opal and total organic carbon. Relatively low lithic particles (coarse and poorly sorted) and iron fluxes during these glacial periods indicate that the increased diatom productivity did not result from dust-stimulated fertilization events. We argue that glacial fertilization occurred through the advection of nutrient-rich waters from the Southern Ocean. In contrast, glacial periods after 1.85 Ma are characterized by enhanced dust transport of finer lithic particles acting as a new source of nutrients in the EEP. The benthic ecosystem shows dissimilar responses to the high productivity recorded during glacial periods before and after 1.85 Ma, which suggests that the transport processes delivering organic matter to the deep sea also changed. Different depositional processes are interpreted to be the result of two distinct glacial positions of the Intertropical Convergence Zone (ITCZ). Before 1.85 Ma, the ITCZ was above the equator, with weak local winds and enhanced wet deposition of dust. After 1.85 Ma, the glacial ITCZ was displaced northward, thus bringing stronger winds and stimulating upwelling in the EEP. The glacial period at 1.65 Ma with the most intense LDOs supports a rapid southward migration of the ITCZ comparable to those glacial periods before 1.85 Ma.
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Sarmento H., C. Morana, J.M. Gasol
ISME Journal, 10, 2582-2592. DOI: 10.1038/ismej.2016.66 (BibTeX: sarmento.etal.2016)
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Benavides M., S. Bonnet, N. Hernández, A.M. Martínez-Pérez, M. Nieto-Cid, X.A. Álvarez-Salgado, I. Baños, M.F. Montero, I.P. Mazuecos, J.M. Gasol, H. Osterholz, T. Dittmar, I. Berman-Frank, J. Arístegui.
Global Biogeochemical Cycles, 30, 952-961. DOI: 10.1002/ 2015GB005326 (BibTeX: benavides.etal.2016)
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Forster D., M. Dunthorn, F. Mahé, J.R. Dolan, S. Audic, D. Bass, L. Bittner, C. Boutte, R. Christen, J.M. Claverie, J. Decelle, B. Edvardsen, E. Egge, W. Eikrem, A. Gobet, W.H.C.F. Kooistra, R. Logares, R. Massana, M. Montresor, F. Not, H. Ogata, J. Pawlowski, M.C. Pernice, S. Romac, K. Shalchian-Tabrizi, N. Simon, T.A. Richards, S. Santini, D. Sarno, R. Siano, D. Vaulot, P. Wincker, A. Zingone, C. de Vargas, T. Stoeck
FEMS Microbiology, Ecology, 92, 8, 1-11. DOI: 10.1093/femsec/fiw120 (BibTeX: forster.etal.2016)
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Casas i Güell E.,
PhD thesis. Director/es: N. Teixidó Ullod, E. Cebrian i Pujol. (BibTeX: casasiguell.2016a)
Resum: Veure
Increasing anthropogenic pressures and its effects on marine ecosystems urge enhanced knowledge and understanding of the current state of marine biodiversity. This baseline information is pivotal to establish the actual state, detect future changes, explore possible trends and propose adequate management actions for marine ecosystems. Coralligenous outcrops are a highly diverse and structurally complex habitat faced with major threats in the Mediterranean Sea. Despite its ecological, aesthetic and economic value, coralligenous biodiversity patterns are still poorly understood. Information on the spatial and temporal variability of the composition and structure of coralligenous assemblages is scarce for most regions. Specially, data on species diversity and structure in coralligenous outcrops dominated by Corallium rubrum and Paramuricea clavata are essentially lacking. Gathering these data is needed to build robust baselines in order to assess the responses of this highly threatened habitat to anthropogenic disturbances (e.g. mass mortality events, sedimentation and invasive species). There is currently no single sampling method that has been demonstrated to be sufficiently representative to ensure adequate community assessment and monitoring in this habitat. In Chapter 3, we propose a rapid non-destructive protocol for biodiversity assessment and monitoring of coralligenous outcrops providing good estimates of its structure and species composition, based on photographic sampling and the determination of presence/absence of macrobenthic species. We followed a hierarchical sampling survey, covering more than 400 km of rocky coasts in NW Mediterranean (Catalan coast –Spain-, Provence and NW Corsica –France). This approach allowed us to determine the minimal sampling area for each assemblage (5000 cm2 for P. clavata and 2500 cm2 for C. rubrum). In addition, we concluded that 3 replicates provided an optimal sampling effort in order to maximize the species number and to assess the main biodiversity patterns of studied assemblages in variability studies requiring replicates. We followed the mentioned hierarchical sampling survey in Chapter 3 to characterize the spatial and temporal variability of structure, composition, abundance and diversity of perennial species inhabiting coralligenous outcrops dominated by C. rubrum or P. clavata (Chapter 4 and Chapter 5 respectively). In Chapter 4 spatial variability of species composition, structure and diversity in coralligenous assemblages dominated by C. rubrum was assessed. We also pooled the identified species/taxa into morphofunctional groups according to their life-span and growth to characterize the structural complexity of the assemblages. Finally, we analyzed the number, size and shape of patches (landscape pattern indices) for each group in order to describe the spatial arrangement within the C. rubrum assemblage. Landscape pattern indices in C.rubrum assemblages exhibited important differences among sites in the same locality whereas localities showed similar values. In Chapter 5, the spatial and temporal variability of species composition, structure and diversity in coralligenous assemblages dominated by P. clavata was assessed. According to ordination analyses, species composition and the structural complexity of coralligenous assemblages differed consistently across all spatial scales considered. The lowest and the highest variability were found among localities (100 km) and within sites (1-5 km), respectively. Despite the differences, the sites displayed high similarity (average similarity 55.7 %) and shared approximately 50 % of the species. Similarly, differences in diversity indices (alpha, beta and gamma) were found. Furthermore, the study of P. clavata addressed diversity patterns over 5-year period. Overall, no temporal changes were detected in either species composition or the morphofunctional groups considered. In Chapter 6, we showed how an extreme storm event affected the dynamics of benthic coralligenous outcrops in the NW Mediterranean Sea using data acquired before (2006–2008) and after the impact (2009–2010) at four different sites. The loss of cover of benthic species resulted between 22% and 58%. The damage across these species (e.g. calcareous algae, sponges, anthozoans, bryozoans, tunicates) was uneven, and those with fragile forms were the most impacted, showing cover losses up to 50 to 100%. Interestingly, small patches survived after the storm and began to grow slightly during the following year. In contrast, sheltered sites showed no significant changes in all the studied parameters, indicating no variations due to the storm. Overall, the results presented in this thesis furnishes a basis for the implementation of monitoring schemes of coralligenous assemblages complementing the scarce available information on assemblage composition and structure of the emblematic Mediterranean coralligenous outcrops dominated by C. rubrum and P. clavata over large spatial scales. Our results demonstrate the moderate spatial and the extremely low temporal variability in biodiversity patterns in the NW Mediterranean region, providing the first baselines for detecting potential changes due to global change effects. We also provide new insights into the responses of these assemblages to a large and rare extreme event. The development of similar sampling schemes in other Mediterranean regions will provide a global view of the biodiversity of coralligenous outcrops.
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Acevedo Dudley M.J.,
PhD thesis. Director/es: A. Calbet, V. Fuentes. Barcelona. (BibTeX: acevedodudley.2016a)
Resum: Veure
Over the last years, the sightings of the cubomedusa Carybdea marsupialis have increased in the Mediterranean Sea and this has been linked to an increase in its abundance. Consequently, this phD thesis addresses some questions regarding the possible causes and effects of this phenomenon. Firstly, the taxonomy and distribution of the species have been revised and updated. Moreover, laboratory experiments were conducted to study the development and ecophysiology of this animal. These results were complemented with field studies on the gut contents and trophic markers of C. marsupialis. Finally, the results of a four years monitoring in the coast of Denia (Spain), as well as the sightings of the species reported along the Mediterranean, provided solid evidence on the main factors affecting the distribution of C. marsupialis. Overall, the species seems to be favoured by high nutrient inputs from anthropogenic origin, and other human activities as coastal constructions. Los avistamientos de la cubomedusa Carybdea marsupialis han aumentado en el Mar Mediterráneo en los últimos años, hecho que ha sido atribuido a un incremento en su abundancia. El objetivo de esta tesis doctoral es responder algunas preguntas relacionadas con las posibles causas y efectos de este fenómeno. En primer lugar, se han actualizado la taxonomía y la distribución de la especie. Además, se han llevado a cabo experimentos relacionados con su desarrollo y ecofisiología. Estos resultados se han complementado con estudios de sus contenidos estomacales y marcadores tróficos en el campo. Finalmente, un monitoreo durante cuatro años en la costa de Denia (España), junto con los avistamientos de esta cubomedusa en el Mediterráneo, han proporcionado evidencias sólidas acerca de los factores principales que afectan la distribución de C. marsupialis. En general, la especie parece verse favorecida por el aporte de nutrientes de origen antropogénico, y por otras actividades humanas como las construcciones costeras.
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Pérez G.L., M. Galí, S-J. Royer, H. Sarmento, J.M. Gasol, C. Marrase, R. Simó
Deep-Sea Research. Part I: Oceanographic Research Papers, 114, 111-127. DOI: 10.1016/j.dsr.2016.05.011 (BibTeX: perez.etal.2016)
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Rosón G., E.F. Guallart, F.F. Pérez, A.F. Ríos
Journal of Marine Systems, 158, 45-51. DOI: 10.1016/j.jmarsys.2016.01.011 (BibTeX: roson.etal.2016)
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Galí M., D. Kieber, C. Romera-Castillo, J.D. Kinsey, E. Devred, G.L. Pérez, G.R. Westby, C. Marrasé, M. Babin, M. Levasseur, C. Duarte, S. Agusti, R. Simó
Environmental Science and Technology, 50, 24, 13361-13370. DOI: 10.1021/acs.est.6b04278 (BibTeX: gali.etal.2016)
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Catalá T.S., I. Reche, C.L. Ramón, A.López-Sanz, M. Álvarez, E. Calvo, X.A. Álvarez-Salgado
Geophysical Research Letters, 43, 14, 7639-7648. DOI: 10.1002/2016GL069878 (BibTeX: catala.etal.2016b)
Resum: Veure
Detailed examination of the absorption spectra from dark ocean samples allowed us to identify and deconvolve two distinct chromophores centered at 302 nm (UV) and 415 nm (visible) from the exponential decay curve characteristic of humic substances. The UV chromophore was ubiquitous in intermediate and deep waters, and it has been proposed as the secondary absorption peak of nitrate. The visible chromophore was prominent at the central and intermediate water masses of the North Pacific, and it has been proposed as cytochrome c. Subtraction of the modeled absorption spectra of the two chromophores from the measured absorption spectrum of the samples leads to a spectral slope overestimation by 13.3 ± 6.0% for S275–295 and 14.8 ± 10.6% for S350–400. To only consider the chromophoric fraction of DOM, the absorption spectra of nitrate should be subtracted in samples with a [NO3−]:a302 ratio > 70 µM m.
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Busch J.A., R. Bardaji, L. Ceccaroni, A. Friedrichs, J. Piera, C. Simon, P. Thijsse, M. Wernand, H.J. van der Woerd, O. Zielinski
Remote Sensing, 8, 11, 879. DOI: 10.3390/rs8110879 (BibTeX: busch.etal.2016a)
Resum: Veure
Marine processes are observed with sensors from both the ground and space over large spatio-temporal scales. Citizen-based contributions can fill observational gaps and increase environmental stewardship amongst the public. For this purpose, tools and methods for citizen science need to (1) complement existing datasets; and (2) be affordable, while appealing to different user and developer groups. In this article, tools and methods developed in the 7th Framework Programme of European Union (EU FP 7) funded project Citclops (citizens’ observatories for coast and ocean optical monitoring) are reviewed. Tools range from a stand-alone smartphone app to devices with Arduino and 3-D printing, and hence are attractive to a diversity of users; from the general public to more specified maker- and open labware movements. Standardization to common water quality parameters and methods allows long-term storage in regular marine data repositories, such as SeaDataNet and EMODnet, thereby providing open data access. Due to the given intercomparability to existing remote sensing datasets, these tools are ready to complement the marine datapool. In the future, such combined satellite and citizen observations may set measurements by the engaged public in a larger context and hence increase their individual meaning. In a wider sense, a synoptic use can support research, management authorities, and societies at larg.
Paraules clau: citizen’s applications for earth surveillance, smartphones, open labware, interoperability, aquatic optics, incentives to mobilize the crowd, emerging technologies, data repositories, DIY, open access
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Moullec F., F. Ben Rais Lasram, M. Coll, F. Guilhaumon, F. Le Loc’h, Y.-J. Shin
In: The Mediterranean Region under Climate Change: A Scientific Update, IRD. Chap. 2(1.4). 249-261. ISBN: 978-2-7099-2219-7 (BibTeX: moullec.etal.2016f)
Resum: Veure
There is considerable evidence that Mediterranean marine species have been shifting their ranges, migration patterns, seasonal activities and periodicities, abundances, growth and mortality rates, and consequently their trophic interactions in response to climate change and variability. These responses may ultimately have significant consequences for ecosystem productivity, biodiversity and functioning and hence for the overall goods and ecosystem services they provide, especially the production of living resources (Kirby & Beaugrand 2009, Doney et al. 2012). Climate change is an additional pressure on marine ecosystems that are already subject to many anthropogenic disturbances such as fishing activities. This is especially true in the Mediterranean Sea, where a series of human impacts co-occur and interact (Coll et al. 2010, Micheli, Halpern, et al. 2013). The consequences of climate change for marine resources need to be evaluated in this context and research and management need to take interactions between fishing, other human impacts, and climate into account (Brander 2010, Perry et al. 2010). This chapter thus has three aims: (i) to investigate the synergy between climate and fishing (a major human impact onMediterranean marine ecosystems) and, using some examples from the Mediterranean Sea, to highlight how these two factors interact, from the individual to the ecosystem scale, (ii) to assess and quantify the consequences of climate change for the composition of fishery catches in theMediterranean Sea, and (iii) to address the consequences of climate change for the management tools and strategies implemented in the region.
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Moullec F., F. Ben Rais Lasram, M. Coll, F. Guilhaumon, G. Halouani, T. Hattab, F. Le Loc’h, Y.-J. Shin
In: The Mediterranean Region under Climate Change : A Scientific Update, IRD. Chap. 2(1.3). 229-248. ISBN: 978-2-7099-2219-7 (BibTeX: moullec.etal.2016e)
Resum: Veure
Temperature has a major direct effect on the physiology, growth, reproduction, recruitment and behavior of poikilothermic organisms such as fish. It affects many physiological processes ranging from damaging proteins to disrupting organ function. Environmental changes, especially climate warming, may thus strongly influence the abundance and biogeography of fish through species-specific physiological thresholds of temperature tolerance, or through responses to changes in other trophic levels (Perry et al. 2005, Sabates et al. 2006, Rijnsdorp et al. 2009). Organisms tend to adapt to local environmental temperatures, with optimal physiological responses matching temperatures that are close to the environmental average (Hoegh-Guldberg & Bruno 2010). In this context, shifts in the spatial distribution range of marine organisms are among the most perceptible consequences of climate change at the world scale, with potentially significant impacts on commercial fisheries (Perry et al. 2005), on food webs and ecosystem functioning (Doney et al. 2012, Albouy et al. 2014), and on biodiversity as a whole (Harley 2011, Bellard et al. 2012). The warming of the Mediterranean Sea affects the fitness of marine biota as already shown by records of changes in abundance, survival and fertility,phenology and species migration (Marbà et al. 2015). Population abundance and survival are the biological variables are the most frequently reported impacts of Mediterranean warming, followed by migration of native and introduced species (Marbà et al. 2015). However, the sensitivity of Mediterranean biota to warming varies across taxonomic groups (Marbà et al. 2015), from primary producers to high trophic levels, with possible synergistic effects with other anthropogenic impacts such as high exploitation (Harley et al. 2006). In this chapter, we use examples to analyze the expected impacts of climate change on marine organisms in the Mediterranean Sea, with a focus on fish, and to investigate possible responses from individual to ecosystem level. It is important to bear in mind that in the Mediterranean Sea, the effects of climate change occur in parallel with other human-driven effects such as overfishing, pollution, and habitat degradation (Coll et al. 2010), and can have cumulative effects, frequently of synergistic nature (Calvo et al. 2011).
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Marañón E., W.M. Balch, P. Cermeño, N. González, C. Sobrino, A. Fernández, M. Huete-Ortega, D.C. López-Sandoval, M. Delgado, M. Estrada, M. Álvarez, E. Fernández-Guallart, C. Pelejero
Limnology and Oceanography, 61, 4, 1345-1357. DOI: 10.1002/lno.10295 (BibTeX: maranon.etal.2016)
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Aguirre de Cárcer D., C. Pedrós-Alió, D.A. Pearce, A. Alcamí
Frontiers in Microbiology, 7, 337, 1-11. DOI: 10.3389/fmicb.2016.00337 (BibTeX: aguirredecarcer.etal.2016)
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Bosch-Belmar M., F. Giomi, A. Rinaldi, A. Mandich, V. Fuentes, S. Mirto, G. Sarà, S. Piraino
Scientific Reports, 6, 27929, 1-9. DOI: 10.1038/srep27929 (BibTeX: boschbelmar.etal.2016a)
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Alonso B., G. Ercilla, D. Casas, D.A.V. Stow, F.J. Rodríguez-Tovar, J. Dorador, F.J. Hernández-Molina
Marine Geology, 377, 77-94. DOI: 10.1016/j.margeo.2015.12.016 (BibTeX: alonso.etal.2016c)
Resum: Veure
Pleistocene succession at Sites U1386 and U1387 (IODP 339) from palaeo-moat and drift domains of the Faro Drift has been examined to characterize the lithofacies and to identify the most useful criteria for distinguishing between contourite and gravity-flow deposits. Three lithofacies, A, B, and C, are defined based on a combination of sedimentological and mineralogical analyses. The dominant lithofacies A corresponds to contourite deposits; lithofacies B and C comprise turbidites and debrites respectively. Three main criteria have been utilized to distinguish between these deposits: (i) the vertical trend of the grain-size and the sedimentary structures. The contourites show complete sequences (C1 to C5 divisions) and truncate sequences (basecut-out divisions, e.g., C3–C2–C1, and C3). The turbidites display mainly Td–Te divisions, although Tc division is also present to a lesser extent. The debrites display deformational and shearing structures; (ii) the modal frequency distribution. The contourite sequences show similar mode grain-size values in different textures suggesting that the steady conditions of supply are maintained over time. In contrast, turbidite and debrite sequences display different modes, primarily conditioned by mixing of components from allochthonous sources and their downslope gravitational transport; (iii) the sediment composition (clay mineral, bulk mineral and sand fraction) and provenance that reflect long- and short-distance transport modes. Most of the terrigenous components of the contourites come from the Guadalquivir drainage basin, whereas for the turbidites and debrites these are sourced from the neighbouring fluvial drainage basins (Guadiana, Tinto-Odiel). The biogenic components in the latter indicate shallow depositional environments prior to seafloor failure. The spatial and temporal distributions of the lithofacies reflect the different (palaeo) environments of the Faro Drift. Debrite and incomplete turbidite sequences characterize the palaeo-moat domain during the Early Pleistocene. Complete contourite sequences (C1 to C5) and basecut-out sequences (C3–C4–C5, and C3) characterize the proximal palaeo-drift domain during the Early and Middle Pleistocene and the complete contourite sequences represent the distal drift domain during the Late Pleistocene.
Paraules clau: Gulf of Cadiz, Contourites, Turbidites, Debrites, Grain-size, Bulk mineral, Clay mineral
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Sala M.M., F. Aparicio, V. Balagué, J.A. Boras, E. Borrull, C. Cardelús, L. Cros, A. Gomes, A. López-Sanz, A. Malits, R.A. Martínez, M. Mestre, J.M. Movilla, H. Sarmento, E. Vázquez-Domínguez, D. Vaqué, J. Pinhassi, A. Calbet, E. Calvo, J.M. Gasol, C. Pelejero, C. Marrasé
ICES Journal of Marine Science, 73, 3, 670-679. DOI: 10.1093/icesjms/fsv130 (BibTeX: sala.etal.2016a)
Resum: Veure
We investigated the effects of an increase in dissolved CO2 on the microbial communities of the Mediterranean Sea during two mesocosm experiments in two contrasting seasons: winter, at the peak of the annual phytoplankton bloom, and summer, under low nutrient conditions. The experiments included treatments with acidification and nutrient addition, and combinations of the two. We followed the effects of ocean acidification (OA) on the abundance of the main groups of microorganisms (diatoms, dinoflagellates, nanoeukaryotes, picoeukaryotes, cyanobacteria, and heterotrophic bacteria) and on bacterial activity, leucine incorporation, and extracellular enzyme activity. Our results showed a clear stimulation effect of OA on the abundance of small phytoplankton (pico- and nanoeukaryotes), independently of the season and nutrient availability. A large number of the measured variables showed significant positive effects of acidification in summer compared with winter, when the effects were sometimes negative. Effects of OA were more conspicuous when nutrient concentrations were low. Our results therefore suggest that microbial communities in oligotrophic waters are considerably affected by OA, whereas microbes in more productive waters are less affected. The overall enhancing effect of acidification on eukaryotic pico- and nanophytoplankton, in comparison with the non-significant or even negative response to nutrient-rich conditions of larger groups and autotrophic prokaryotes, suggests a shift towards medium-sized producers in a future acidified ocean.
Paraules clau: Acidification, eutrophication, Mediterranean sea, mesocosm, microorganisms
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Cartes J.E., A. Soler-Membrives, C. Stefanescu, A. Lombarte, M. Carrassón
Deep-Sea Research. Part I: Oceanographic Research Papers, 109, 123-136. DOI: 10.1016/j.dsr.2015.11.001 (BibTeX: cartes.etal.2016a)
Resum: Veure
The contributions of allochthonous inputs of food (food falls, plastics and other anthropogenic remains) in the diets of large fish (6 teleosteans, 3 sharks) were analyzed for depths between 500 and 2300 m in the deep Balearic basin (western Mediterranean). The analyses were based on gut contents. The identification was based on a multi-analytic approach, comprising morphological features (including morphometric analysis) and molecular genetics (DNA barcoding method). Remains of a number of anthropogenic, inorganic materials (microplastic fibres, plastic bags and cartons) appeared regularly in the guts of deep-sea fish (e.g., in Trachyrhynchus scabrus and Mora moro), though always at low occurrence (9.1% of fish at most) and negligible weights (< 2%W of diet). In our sampling, covering an area of ca. 12 km2, large food falls contribute only a little to fish diets by weight, W, e.g., in shark diets they represented 4.5%W for Centroscymnus coelolepis and 11%W for Galeus melastomus. However, the importance of food falls (e.g., cetacean blubber and carcharhinid shark remains) was substantial locally (up to 70.8%W of C. coelolepis diet) particularly near canyons. The arrival of livestock remains (beef flesh, goat ribs and vertebrae) was shown by molecular analyses to contributed to deep-sea shark diets (ca. 5.5%W) comparably to natural food falls. These remains, which originate from human activity, may locally alter the food webs of oligotrophic environments like that of the deep Mediterranean. Food falls of both natural and anthropogenic origin were mainly found in fish collected close to canyon axes. The only cetacean fall documented in the deep Balearic Basin was also near a canyon, the carcass of a small (ca. 1.2 m) striped dolphin, Stenella coeruleoalba, collected in a haul at 1750 m off Barcelona
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Boj M., F. Chauvigné, J. Cerdà
Biology of Reproduction, 93, 2, DOI: 10.1095/biolreprod.115.131524 (BibTeX: boj.etal.2016a)
Resum: Veure
In marine teleosts, such as the gilthead seabream, several aquaporin paralogs are known to be expressed during the hyperosmotic induction of spermatozoon motility in seawater. Here, we used immunological inhibition of channel function to investigate the physiological roles of Aqp1aa, Aqp1ab, and Aqp7 during seabream sperm activation. Double immunofluorescence microscopy of SW-activated sperm showed that Aqp1aa and Aqp7 were respectively distributed along the flagellum and the head, whereas Aqp1ab accumulated in the head and in discrete areas toward the anterior tail. Inhibition of Aqp1aa reduced the rise of intracellular Ca2+, which is independent of external Ca2+ and normally occurs upon activation, and strongly inhibited sperm motility. Impaired Aqp1aa function also prevented the intracellular trafficking of Aqp8b to the mitochondrion, where it acts as a peroxiporin allowing H2O2 efflux and ATP production during activation. However, restoring the Ca2+ levels with a Ca2+ ionophore in spermatozoa with immunosuppressed Aqp1aa function fully rescued mitochondrial Aqp8b accumulation and sperm motility. In contrast, exposure of sperm to Aqp1ab and Aqp7 antibodies did not affect motility during the initial phase of activation, but latently compromised the trajectory and the pattern of movement. These data reveal the coordinated action of spatially segregated aquaporins during sperm motility activation in a marine teleost, where flagellar-localized Aqp1aa plays a dual Ca2+-dependent role controlling the initiation of sperm motility and the activation of mitochondrial detoxification mechanisms, while Aqp1ab and Aqp7 in the head and anterior tail direct the motion pattern.
Paraules clau: aquaporin, calcium, mitochondria, motility, spermatozoa, teleost, trafficking
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Trindade A., A. Peliz, J. Dias, L. Lamas, P. Oliveira, T. Cruz
Continental Shelf Research, 127, 12-27. DOI: 10.1016/j.csr.2016.08.04 (BibTeX: trindade.etal.2016a)
Resum: Veure
With favoredoffshoreanddownstreamadvection,thequestionofwhichphysicalmechanismmay promoteonshoretransportoflarvaeinupwellingsystemsisofcentralinterest.Wehaveconducteda semi-realistic highresolution(0.25km)numericalstudyofLagrangiantransportsacrosstheinner-shelf under upwelling-favorablewindforcingconditions,focusingontheshelfareaoftheSouthwestern Portuguese coast,intheleeofCapeSines.Weaddour findings toseveralyearsofbiologicalobservations of C. montagui, aplanktonicspecieswithhigherrecruitmentduringtheupwellingpeaktimelywiththe daylight flood. Simulationscovera fifteendaysperiodduringthesummerof2006.WefocusedonSpring and Neaptideperiodsandobservedupfrontdifferencesbetweensimulationsandtheinsituobserva- tions. However,themodeliscapableofrepresentingthemaindynamicsoftheregion,namelythere- petitivecharacteroftheinner-shelfcurrents.We find thatthecross-shore flow variessignificantly inthe daily cycle,andlocallywithinascaleofafewkilometersinassociationwithlocaltopographyandthe presence ofthecape.Weconsidertheregionimmediatelyintheleeofthecapetobeanupwelling shadow wherethelarvaebecameretained,andfoundthattidallytiedmigrationprovesbeneficial for successful recruitmentduringthespringtidesperiod.Ourworksuggestedthatthewindisnottheonly mechanism responsibleforthedailyvariabilityofthecross-shoreexchange.However,itssharpreversal at middayiscriticalfortheadvectionoflarvaetowardsthecoast.
Paraules clau: Inner-shelfcirculation Cross-shoretransport Coastal upwelling Lagrangian model Vertical migration
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Dañobeitia J., R. Bartolomé, M. Prada, F. Nuñez-Cornú, D. Córdoba, W.L. Bandy, F. Estrada, A.L. Cameselle, D. Nuñez, A. Castellón, J.L. Alonso, C. Mortera, M. Ortiz
Pure and Applied Geophysics, 173, 10, 3553-3573. DOI: 10.1007/s00024-016-1388-7 (BibTeX: danobeitia.etal.2016a)
Resum: Veure
Processing and analysis of new multichannel seismic records, coincident with wide-angle seismic profiles, acquired in the framework of the TsuJal project allow us to investigate in detail the complex structure of the oceanic domain in the collision zone between Rivera Plate and Block Jalisco at its northern termination. The subducting Rivera Plate, which is overridden by the North American Plate–Jalisco Block, is clearly identified up to 21.5°N (just south of Maria Magdalena Island) as a two clear reflections that we interpret as the interplate and Moho discontinuities. North of the Tres Marias Islands the seismic images display a different tectonic scenario with structures that are consistent with large faulting and rifted margin. A two-dimensional velocity approach for the crustal geometry is achieved using joint refraction/reflection travel time tomography, the uncertainty of the results is assessed by means of Monte Carlo analysis. Our results show an average oceanic crustal thickness of 6–7 km with a moderate increase towards the Jalisco Block, an anomalous thick layers (~3.0 km) displaying a relatively low velocity (~5.5 km/s) underneath Maria Magdalena Rise, and an estimated Moho depth deeper than 15 km in the collision zone between Rivera Plate and Jalisco Block. We have also determined an anomalous crust on the western flank of the Tres Marias Islands, which may be related to the initial phases of continental breakup of the Baja California Peninsula and Mexico mainland. High-resolution bathymetry provides remarkable images of intensive slope instabilities marked by relatively large slides scars of more than 40 km2 extent, and mass-wasting deposits probably triggered by the intense seismicity in the area.
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Cornejo-Castillo F.M., A.M. Cabello, G. Salazar, P. Sánchez-Baracaldo, G. Lima-Mendez, P. Hingamp, A. Alberti, S. Sunagawa, P. Bork, C. de Vargas, J. Raes, C. Bowler, P. Wincker, J.P. Zehr, J.M. Gasol, R. Massana, S.G. Acinas
Nature Communications, 7, 11071, 1-9. DOI: 10.1038/ncomms11071 (BibTeX: cornejocastillo.etal.2016)
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Martin P., F. Maynou, L. Recasens, A. Sabatés
Fisheries Oceanography, 25, 3, 229-240. DOI: 10.1111/fog.12147 (BibTeX: martin.etal.2016a)
Resum: Veure
In the Mediterranean, blue whiting, Micromesistius poutassou, constitutes a traditional fisheries resource. Over several decades, blue whiting landings in the Catalan coast (northwestern Mediterranean) have displayed cyclical variations, of c. 6 yrs, slightly decreased to five in the last two decades, as shown through wavelet analysis. These fluctuations have persisted under very different levels of fishing effort. This study evaluates the hypothesis that deep-water formation in the adjacent Gulf of Lions, and the enhanced primary productivity related to it, determines recruitment strength in blue whiting that results ultimately in the observed periodicity of the blue whiting landings. The link between landings and environmental drivers was explored using lagged cross-correlations, with 0- and 1-yr lag. The variables considered included large-scale indices [North Atlantic Oscillation (NAO) and the Atlantic Multi-decadal Oscillation (AMO)], Mediterranean climate indices [MO and Western Mediterranean Oscillation (WeMO)], and variables defining the local environmental conditions in the northwestern Mediterranean (sea-air heat flux, winter air temperature anomaly and Rhône river runoff). Significant correlations were only found between landings (1961–2011) and sea-air heat flux, which is generally taken as an indicator of processes of deep water convection, at 0 and 1-yr lag. These results suggest that the observed fluctuations in blue whiting landings respond to oceanographic processes taking place in the Gulf of Lions.
Paraules clau: Cyclic variations, deep-water formation, Micromesistius poutassou, northwestern Mediterranean
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Mitra A., K.J. Flynn, U. Tillmann, J.A. Raven, D. Caron, D.K. Stoecker, F. Not, P.J. Hansen, G. Hallegraeff, R. Sanders, S. Wilken, G. McManus, M. Johnson, P. Pitta, S. Vage, T. Berge, A. Calbet, F. Thingstad, H.J. Jeong, J.-A. Burkholder, P.M. Glibert, E. Granéli, V. Lundgre
Protist, 167, 2, 106-120. DOI: 10.1016/j.protis.2016.01.003 (BibTeX: mitra.etal.2016a)
Resum: Veure
Arranging organisms into functional groups aids ecological research by grouping organisms (irrespective of phylogenetic origin) that interact with environmental factors in similar ways. Planktonic protists traditionally have been split between photoautotrophic “phytoplankton” and phagotrophic “microzooplankton”. However, there is a growing recognition of the importance of mixotrophy in euphotic aquatic systems, where many protists often combine photoautotrophic and phagotrophic modes of nutrition. Such organisms do not align with the traditional dichotomy of phytoplankton and microzooplankton. To reflect this understanding, we propose a new functional grouping of planktonic protists in an eco-physiological context: (i) phagoheterotrophs lacking phototrophic capacity, (ii) photoautotrophs lacking phagotrophic capacity, (iii) constitutive mixotrophs (CMs) as phagotrophs with an inherent capacity for phototrophy, and (iv) non-constitutive mixotrophs (NCMs) that acquire their phototrophic capacity by ingesting specific (SNCM) or general non-specific (GNCM) prey. For the first time, we incorporate these functional groups within a foodweb structure and show, using model outputs, that there is scope for significant changes in trophic dynamics depending on the protist functional type description. Accordingly, to better reflect the role of mixotrophy, we recommend that as important tools for explanatory and predictive research, aquatic food-web and biogeochemical models need to redefine the protist groups within their frameworks.
Paraules clau: Plankton functional types (PFTs), phagotroph, phototroph, mixotroph, phytoplankton, microzoo-plankton
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Farrant G.K., H. Doré, F.M. Cornejo-Castillo, F. Partensky, M. Ratin, M. Ostrowski, F.D. Pitt, P. Wincker, D.J. Scanlan, D. Iudicone, S.G. Acinas, L. Garczarek
Proceedings of the National Academy of Sciences of the United States of America, 113, 24, E3365-E3374. DOI: 10.1073/pnas.1524865113 (BibTeX: farrant.etal.2016)
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Grieco G., W. Lin, M. Migliaccio, F. Nirchio, M. Portabella
International Journal of Remote Sensing, 37, 21, 5086-5104. DOI: 10.1080/01431161.2016.1226525 (BibTeX: grieco.etal.2016d)
Resum: Veure
Sea wind and sea state estimation by synthetic aperture radar (SAR) measurements is a topic of relevance both on the scientific and user side. The new European Space Agency (ESA) Sentinel-1 constellation is meant to support marine studies and ensure highquality data. In this paper, we investigate the azimuth cut-off (λC) sea wind speed and significant wave height retrieval approach by taking benefit of two sets of multi-look SAR images with incidence angles varying from 20° to 45°. The images have been co-located with sea surface wind measurements acquired by the scatterometer onboard the Chinese satellite HY-2A (HSCAT) and with the European Centre for Medium Range Weather Forecast (ECMWF) operational model output. This study is meant to analyse both the empirical dependency of SAR λC on significant wave height (Hs) and wind speed (U). Several fitting geophysical model functions (λC-GMFs) are proposed and discussed. The results show that λC is strongly correlated with the significant wave height in all sea state conditions, while the correlation with the wind speed is only high for fully developed sea states. The azimuth cut-off based significant wave height retrievals are compared with independent National Data Buoy Centre (NDBC) network observations, showing a root mean square difference of about 0.5 m.
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Lønborg C., L.A. Cuevas, T. Reinthaler, G.J. Herndl, J.M. Gasol, X.A.G. Morán, N.R. Bates, X.A. Álvarez-Salgado
Frontiers in Marine Science, 3, 90, 1-9. DOI: 10.3389/fmars.2016.00090 (BibTeX: lonborg.etal.2016)
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Farré M., V.M. Tuset, J.E. Cartes, E. Massutí, A. Lombarte
Progress in Oceanography, 147, 22-37. DOI: 10.1016/j.pocean.2016.07.006 (BibTeX: farre.etal.2016a)
Resum: Veure
The morphological and functional traits of fishes are key factors defining the ecological and biological habits of species within ecosystems. However, little is known about how the depth gradient affects these factors. In the present study, several demersal fish assemblages from the Balearic Islands (western Mediterranean Sea) along a wide depth range (40–2200 m) were morphologically, functionally and ecologically described. The morphological characterization of communities was performed using geometric morphometric methods, while the functional structures were obtained by the functional categorization of species and the application of principal coordinates analysis (PCoA). The results revealed that morphospaces presented less richness of body forms as depth increases, although they showed a progressive spreading of species toward the periphery, with a proliferation of more extreme body traits, demonstrating lower morphological redundancy. In addition, a trend toward the elongation of body shape was also observed with depth. Moreover, functional diversity increased with bathymetry up to 1400 m, where it sharply decreased downwards. This decrease was parallel to a progressive fall of H′ (ecological diversity) up to 2200 m. Functional redundancy progressively decreased until the deepest assemblage (more constantly in the deeper levels), which was almost exclusively dominated by benthopelagic wandering species feeding on suprabenthos. Redundancy analysis (RDA) demonstrated that both morphological and functional spaces showed high variation along the bathymetric range. Mantel test indicated that the majority of species presented similar spatial distribution within the morphospace and functional space, although in the functional space the more abundant species were always located at the periphery. These results demonstrate that the assessment of the morpho-functional variation between marine communities helps to understand the processes that affect the structure and functioning of communities, such as resource partitioning, trophic interactions, or interspecific relationships within ecosystem such as coexistence and dominance.
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Beddows D.C.S., M. Dall\'Osto, O.A. Olatunbosun, R.M. Harrison
Atmospheric Environment, 129, 167-175. DOI: 10.1016/j.atmosenv.2016.01.018 (BibTeX: beddows.etal.2016)
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Schiaffino M.R., M.L. Sánchez, M. Gerea, F. Unrein, V. Balagué, J.M. Gasol, I. Izaguirre
Journal of Plankton Research, 38, 1, 64-82. DOI: 10.1093/plankt/fbv105 (BibTeX: schiaffino.etal.2016a)
Resum: Veure
We explored the distribution patterns of bacterial and archaeal abundances at the phylum and class level using catalyzed reporter deposition-fluorescence in situ hybridization (CARD-FISH), examining the among (across 35 water bodies) and within-lake (intra-annual seasonality) patterns in Patagonia (Argentina). Alphaproteobacteria, Betaproteobacteria and Actinobacteria globally dominated the bacterioplankton, whereas Gammaproteobacteria and Archaea never exceeded 3 and 6% of the community, respectively. The different groups showed seasonality, with simultaneous peaks of all bacterial group absolute abundances during late winter or spring, and with peaks of Archaea during winter, late spring and summer. The bacterial groups presented roughly similar relative abundances in all seasons, whereas Archaea varied in their relative contribution to community structure. Multivariate analyses showed that dissolved organic carbon was an important variable structuring the community at the studied taxonomic resolution (using absolute and relative abundances), in both among and within-lake patterns. The absolute abundance of most bacterial groups was significantly higher in mesotrophic and eutrophic systems than in oligotrophic ones (except Actinobacteria), whereas their relative abundances did not change among trophic states (except Bacteroidetes). The lake grouping obtained from CARD-FISH was consistent with previous work using polymerase chain reaction-denaturing gradient gel electrophoresis data: deep oligotrophic lakes clustered together, whereas small and shallow water bodies grouped separately
Paraules clau: Bacteria, Archaea, patagonian water bodies, prokaryotic group distribution patterns, CARD-FISH
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Pons S.,
PhD thesis. Director/es: Jaume Piera, Luigi Ceccaroni. (BibTeX: pons.2016a)
Resum: Veure
Water is the most important resource for living on planet Earth, covering more than 70% of its surface. The oceans represent more than 97% of the planet total water and they are where more than the 99.5% of the living beings are concentrated. A great number of ecosystems depend on the health of these oceans; their study and protection are necessary. Large datasets over long periods of time and over wide geographical areas can be required to assess the health of aquatic ecosystems. The funding needed for data collection is considerable and limited, so it is important to look at new cost-effective ways of obtaining and processing marine environmental data. The feasible solution at present is to develop observational infrastructures that may increase significantly the conventional sampling capabilities. In this study we promote to achieve this solution with the implementation of Citizen Observatories, based on volunteer participation. Citizen observatories are platforms that integrate the latest information technologies to digitally connect citizens, improving observation skills for developing a new type of research known as Citizen Science. Citizen science has the potential to increase the knowledge of the environment, and aquatic ecosystems in particular, through the use of people with no specific scientific training to collect and analyze large data sets. We believe that citizen science based tools —open source software coupled with low-cost do-it-yourself hardware— can help to close the gap between science and citizens in the oceanographic field. As the public is actively engaged in the analysis of data, the research also provides a strong avenue for public education. This is the objective of this thesis, to demonstrate how open source software and low-cost do-it-yourself hardware are effectively applied to oceanographic research and how can it develop into citizen science. We analyze four different scenarios where this idea is demonstrated: an example of using open source software for video analysis where lobsters were monitored; a demonstration of using similar video processing techniques on in-situ low-cost do-it-yourself hardware for submarine fauna monitoring; a study using open source machine learning software as a method to improve biological observations; and last but not least, some preliminar results, as proof of concept, of how manual water sampling could be replaced by low-cost do-it-yourself hardware with optical sensors.
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Catalá T.S., X.A. Álvarez-Salgado, J. Otero, F. Iuculano, B. Companys, B. Horstkotte, C. Romera-Castillo, M. Nieto-Cid, M. Latasa, X.A.G. Morán, J.M. Gasol, C. Marrasé, C.A. Stedmon, I. Reche
Limnology and Oceanography, 61, 1101-1119. DOI: doi: 10.1002/lno.10281 (BibTeX: catala.etal.2016)
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González-MiraI Varó A., M. Solé, A. Torreblanca
Environmental Science and Pollution Research, 23, 20, 20937. DOI: 10.1007/s11356-016-7293-x (BibTeX: gonzalezmiraivaro.etal.2016a)
Resum: Veure
The alerted presence in recent decades of pharmaceuticals has become an issue of environmental concern, and most of the mechanisms of biotransformation and biochemical and physiological responses to them in fish are still unknown, as well as the influence of water temperature in their ability to cope with them. This study aims to detect the main effects of two of the most widespread drugs on a set of physiological and biochemical markers in Solea senegalensis. Sole juveniles acclimatized at 15 and 20 °C were administered an intraperitoneal injection of the non-steroidal anti-inflammatory drug ibuprofen (IB; 10 mg/kg) and the anti-convulsant drug carbamazepine (CBZ; 1 mg/kg). Two days after the injection, liver, muscle and plasma were sampled. Liver enzymatic activities of 15 °C acclimated fish were more responsive to pharmaceuticals than those acclimated at 20 °C, especially for CYP450-related activities (7-ethoxyresorufin (EROD), 7-methoxyresorufin (MROD), 3-cyano-7-ethoxycoumarin (CECOD) and 7-benzyloxy-4-[trifluoromethyl]-coumarin-O-debenzyloxylase (BFCOD)) and uridine diphosphate glucuronosyltransferase (UDPGT). Cytosolic anti-oxidant enzyme activities and glutathione S-transferase (GST) did not show a clear effect of temperature. Glucose and transferase activities in plasma were not affected by the treatments, while ammonium, osmolality and lactate were affected by both pharmaceuticals. Plasma triglycerides were affected in a temperature-dependent manner, and creatinine was only responsive to CBZ injection. HSP70 levels in muscle were only affected by CBZ injection. Some of the physiological identified responses to IB and CBZ are proposed as endpoints in further chronic studies.
Paraules clau: Sole, plasma metabolites, CYP enzymes, anti-oxidant enzymes, HSP70, ibuprofen, carbamazepine
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Villanueva R., E.A.G. Vidal, F.Á. Fernández-Álvarez, J. Nabhitabhata
Plos One. Open acces, 11, 11, e0165334. DOI: 10.1371/journal.pone.0165334 (BibTeX: villanueva.etal.2016a)
Resum: Veure
Cephalopods (nautiluses, cuttlefishes, squids and octopuses) exhibit direct development and display two major developmental modes: planktonic and benthic. Planktonic hatchlings are small and go through some degree of morphological changes during the planktonic phase, which can last from days to months, with ocean currents enhancing their dispersal capacity. Benthic hatchlings are usually large, miniature-like adults and have comparatively reduced dispersal potential. We examined the relationship between early developmental mode, hatchling size and species latitudinal distribution range of 110 species hatched in the laboratory, which represent 13% of the total number of live cephalopod species described to date. Results showed that species with planktonic hatchlings reach broader distributional ranges in comparison with species with benthic hatchlings. In addition, squids and octopods follow an inverse relationship between hatchling size and species latitudinal distribution. In both groups, species with smaller hatchlings have broader latitudinal distribution ranges. Thus, squid and octopod species with larger hatchlings have latitudinal distributions of comparatively minor extension. This pattern also emerges when all species are grouped by genus (n = 41), but was not detected for cuttlefishes, a group composed mainly of species with large and benthic hatchlings. However, when hatchling size was compared to adult size, it was observed that the smaller the hatchlings, the broader the latitudinal distributional range of the species for cuttlefishes, squids and octopuses. This was also valid for all cephalopod species with benthic hatchlings pooled together. Hatchling size and associated developmental mode and dispersal potential seem to be main influential factors in determining the distributional range of cephalopods.
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Roux S., J.R. Brum, B.E. Dutlih, S. Sunagawa, M.B. Duhaime, B.T. Poulos, N. Solonenko, E. Lara, J. Poulain, S. Pesant, S. Kandels-Lewis, C. Dimier, M. Picheral, S. Searson, C. Cruaud, A. Alberti, C.M. Duarte, J.M. Gasol, D. Vaque, P. Bork, S.G. Acinas, P. Wincker, M.B. Sullivan
Nature, 537, 7622, 689-693. DOI: 10.1038/nature19366 (BibTeX: roux.etal.2016)
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del Campo J., L. Guillou, E. Hehenberger, R. Logares, P. López-García, R. Massana
European Journal of Protistology, 55, 4-11. DOI: 10.1016/j.ejop.2016.02.002 (BibTeX: delcampo.etal.2016)
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Grinyó Andreu J.,
PhD thesis. Director/es: J.M.Gili Sardà, A. Gori. (BibTeX: grinyoandreu.2016b)
Resum: Veure
Technological development and increased availability of remotely operated vehicles (ROVs) and manned submersibles have significantly increased accessibility to deep environments revealing the presence of rich and diverse macrobenthic assemblages dominated by suspension feeders. These assemblages have been largely exposed to the impacts of fishing activities (especially bottom trawling) in the Mediterranean Sea. Consequently, it is currently urgent to increase knowledge on their distribution, as well as on the ecology and biology of the main species that constitute these macrobenthic assemblages in order to implement effective management and conservation measures. This thesis addressed the characterization of macrobenthic assemblages in the continental shelf and upper slope (40–360 m depth) of the Menorca Channel through a multidisciplinary approach at different ecological levels. Six macrobenthic assemblages mainly segregated by substrate and depth. Hard substrates hosted sponge grounds and coral gardens, whereas crinoid and brachiopod beds occurred on soft sediments. Highest diversity values were found in the shelf edge, probably as a consequence of the bottom heterogeneity and the constant hydrodynamic conditions. Gorgonians were one of the most important and diverse bioengineering organisms in the Menorca Channel, forming dense assemblages that extended over vast areas. Gorgonian assemblages on the continental shelf and upper slope were mostly monospecific, whereas shelf edge assemblages were highly multispecific. Small colonies were dominant throughout the studied bathymetric range, but in deeper environments intermediate and large colonies were more abundant. The good preservation state of most of the observed benthic assemblages and gorgonian populations is probably related to the low pressure of bottom trawling, which is mostly concentrated in deeper areas of the continental and the exceptional fishing practices exerted by the local artisanal fisherman. Paramuricea macrospina is the most abundant gorgonian species in the Menorca Channel. Throughout its distribution, three different chromatic forms were observed. Two forms occurred on the continental shelf, and a third occurred on the shelf edge. Colony shape, sclerite size and shape, and the genetic variability of mitochondrial markers were compared to elucidate if these chromatic forms represented different taxonomic units. Colony morphology barely changed among the three forms resulting as a high conservative character. Conversely, sclerite size and shape significantly differed amongst the three forms, possibly conditioned by genetic and environmental factors. However, no significant differences were observed in the studied mitochondrial markers. The reproductive cycle, energy storage and metabolic requirements of P. macrospina showed significant differences compared to Mediterranean coastal gorgonians. Its reproductive cycle was delayed 2–3 months respect to shallow species, possibly following the late summer increase in seawater temperature occurring on the Mediterranean continental shelf. Moreover, internal brooding in P. macrospina contrasts with surface brooding in the congeneric Paramuricea clavata. Lipid content was lower and more constant in P. macrospina than in shallow species, and ∂13C and ∂15N composition showed almost no seasonal variation, suggesting that food availability in the continental shelf is lower but more constant than in shallower environments. The high oligotrophic conditions of the Balearic Sea apparently contrasts with the high abundance and diversity of active and passive suspension feeders observed in the Menorca Channel. Indeed, the downward particle fluxes quantified during two consecutive years in the Menorca Canyon were comparatively low within the Mediterranean context, reflecting the oligotrophic nature of the study area and the lack of continental inputs of particulate matter. Hydrodynamic settings and physical processes that cause sediment resuspension appeared to be more important than surface primary production in the control of the magnitude and composition of the total mass flux in the study area, likely playing a major role in determining the distribution of the macrobenthic assemblages.
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Piroddi C.,
PhD thesis. Director/es: M. Coll Monton,. M. del Camino Liquete. (BibTeX: piroddi.2016a)
Resum: Veure
In this thesis I investigated the status of the Mediterranean Sea ecosystem and the sustainability of its marine resources using an interdisciplinary approach, which combined data integration and modelling approaches. Results highlighted a series of commonalities for Mediterranean marine ecosystems: they indicate that ‘small pelagic fishes’, mainly European pilchards and anchovies, both with high biomasses and high proportions in catches, are important structuring species for the Mediterranean ecosystem (at regional, sub-regional and local scales). ‘Large pelagic fishes’ are the main keystone species for both the past and current Mediterranean ecosystem configuration, while ‘sharks’ and ‘medium pelagic fishes’ played a key role in the past, but their ecological role is currently replaced by benthopelagic and benthic cephalopods. In addition, the ‘Mediterranean monk seal’ “Monachus monachus”, where it still occurs, is the species with the highest TL followed by ‘piscivorous cetaceans’ and ‘large pelagic fish’. [...]
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Garrido S., A. Cristovao, C. Caldeira, R. Ben-Hamadou, N. Baylina, H. Batista, E. Saiz, M.A. Peck, A.M.P. Santos
Marine Ecology Progress Series, 559, 131-145. DOI: 10.3354/meps11881 (BibTeX: garrido.etal.2016)
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Schmoker C., F. Russo, G. Drillet, A. Trottet, M.S. Mahjoub, S.H. Hsiao, O. Larsen, K. Tun, A. Calbet
Marine Environmental Research, 119, 176-188. (BibTeX: schmoker.etal.2016)
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Movilla J.I.,
PhD thesis. Director/es: C. Pelejero; E. Calvo. (BibTeX: movilla.2016b)
Resum: Veure
Desde el comienzo de la era industrial, los océanos han absorbido casi un tercio del dióxido de carbono (CO2) liberado a la atmósfera por las actividades antropogénicas, mitigando su efecto invernadero y su influencia en el clima de la Tierra. Sin embargo, una consecuencia de esta absorción es la acidificación del océano (OA), un proceso que ha surgido como potencialmente alarmante para los ecosistemas marinos y se ha convertido en una prioridad el la investigación durante los últimos años. El Mediterráneo es actualmente uno de los mares más afectados del mundo, enfrentándose a muchas presiones antropogénicas. Sin embargo, sigue siendo objeto de debate si el impacto de la OA en este mar semi-cerrado será más fuerte que en el océano global. En esta tesis, contribuimos al conocimiento aún limitado de los efectos de medio a largo plazo de la OA en nueve especies bentónicas clave de los dos ecosistemas calcáreos del Mediterráneo más importantes en términos de diversidad, el coralígeno somero y las comunidades de aguas profundas. Para ello, desarrollamos un sistema para la manipulación experimental del pH en acuarios que nos ha permitido exponer los organismos a diferentes condiciones de pH y temperatura, simulando así los valores actuales y los previstos para el año 2100. Se evaluó la respuesta en la tasa de calcificación, en el estado de la estructura carbonatada de soporte (microestructura, microdensidad y porosidad específica del esqueleto) y en el balance metabólico (contenido en materia orgánica, hidratos de carbono, lípidos y proteínas del tejido) en cada una de las especies. En términos de calcificación, la especie más afectada fue el octocoral Corallium rubrum, exhibiendo una disminución promedio entorno al 59%, seguido de los corales zooxantelados Cladocora caespitosa y Oculina patagonica, con una disminución del 35 y 32%, respectivamente. Curiosamente, los corales azooxantelados mostraron una mayor resistencia a las condiciones acidificadas esperadas para finales de siglo, tanto en el caso de las especies temperadas Astroides calycularis y Leptopsammia pruvoti, como en las especies de aguas frías Lophelia pertusa, Madrepora oculata y Dendrophyllia cornigera. La única excepción fue Desmophyllum dianthus que presentó una reducción significativa del 70% en la calcificación de los especímenes más jóvenes tras la exposición a condiciones acidificadas. Nuestros resultados también muestran un cierto grado de variabilidad especie-específico en la respuesta metabólica, sugiriendo que diferentes estrategias y habilidades para la translocación del balance energético podrían explicar parte de la variabilidad observada en la respuesta de estos organismos a las condiciones de pH bajo. Esta tesis ilustra los efectos variables que la acidificación y el calentamiento global pueden tener en organismos calcificadores marinos pertenecientes a ecosistemas bentónicos Mediterráneos y pone de manifiesto los posibles cambios en la composición de estas comunidades en un futuro próximo.
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Giussani V., E. Costa, D. Pecorino, E. Berdalet, G. De Giampaulis, M. Gentile, V. Fuentes, M. Vila, A. Penna, M. Chiantore, F. Garaventa, S. Lavorano, M. Faimali
Harmful Algae, 57, Part A, 49-58. DOI: 10.1016/j.hal.2016.05.005 (BibTeX: giussani.etal.2016a)
Resum: Veure
The frequency and geographic extension of microalgae and gelatinous zooplankton blooms seem to have been increasing worldwide over recent decades. In particular, the harmful dinoflagellate Ostreopsis cf. ovata and the Schyphozoan jellyfish Aurelia sp. are two of the most frequent and long lasting species forming blooms in the Mediterranean Sea. A kind of interaction among any of their life cycle stages (i.e. planula-polyp-ephyrae vs Ostreopsis cells) can likely occur, although in this area there are no data available on the co-occurrence of these species. The aim of this study was to investigate, for the first time, the potential noxious effect of O. cf. ovata on different life stages of Aurelia sp. (polyps and ephyrae), testing several concentrations of whole algal culture. Rsults of toxicity bioassay highlighted that ephyrae, but not polyps, are affected by this harmful dinoflagellate and comparisons among other model organisms show that Aurelia sp. ephyrae are the most sensitive model organism tested so far (EC50–24 h = 10.5 cells/mL). These findings suggest an interesting scenario on the interaction of these two bloom forming species in the natural marine environment.
Paraules clau: Ostreopsis, Aurelia sp., HABs, Jellyfish bloom, Polyps, Toxicology
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Garcia-Olivares A.,
Scientia Marina, 80S1, 257-268. DOI: 10.3989/scimar.04295.12A (BibTeX: garciaolivares.2016a)
Resum: Veure
A feasible way to avoid the risk of energy decline and to combat climate change is to build a worldwide, 100% renewable energy mix. Renewable energy can be scaled up to the range of 12 electric terawatts (TWe) if 10% of continental shelves are exploited with floating turbines to depths as low as 225 m, 5% of continents with ground turbines, and 5% of the main deserts with concentrating solar power (CSP) farms. However, a globally electrified economy cannot grow much above 12 TWe without approaching the limit of terrestrial copper reserves. New photovoltaic silicon panels do not use silver metallization pastes and could contribute up to 1 TW of decentralized residential power. Hydroelectricity has a potential of 1 TW but a fraction of this would have to be sacrificed for energy storage purposes. Hydro, CSP, wave energy and grid integration at continental scales may be sufficient to fit supply to demand, avoiding intermittency. The renewable energy mix would have an energy return on energy invested about 18, which is 25% lower than the estimated present one. That should be sufficient to sustain an industrialized economy provided that the substitution of electricity for fossil fuels is done intelligently.
Paraules clau: 100% renewable energy; renewable potential; EROEI; material limits; post-carbon economy
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González-Gambau V., E. Olmedo, A. Turiel, J. Martínez, J. Ballabrera, M. Portabella, M. Piles
Remote Sensing of Environment, 180, 205-220. DOI: 10.1016/j.rse.2015.12.032 (BibTeX: gonzalezgambau.etal.2016f)
Resum: Veure
Abrupt changes in the SoilMoisture and Ocean Salinity (SMOS) brightness temperatures, such as those produced by land/sea/ice transitions and Radio-Frequency Interference (RFI) sources, produce artificial rippling patterns (i.e. the so-called Gibbs-like contamination) that propagate through the SMOS-reconstructed image. A nodal sampling technique, focused on the reduction of this kind of contamination by sampling at the points where the perturbation cancels,was introduced by González-Gambau et al. (2015). In thisworkwe showthat the quality of nodal sampling can be largely improved by refining the determination of the nodal grid. In addition, we have carried out an extensive validation of the resulting data over the ocean. Nodal sampling reduces sidelobe levels and ripples in the reconstructed images leading to brightness temperatures in better agreement with the the oretically modeled ones. Validation of the salinity retrievals against close-to-surface Argo salinity observations shows that nodal sampling leads to improved salinity retrievals in open ocean,while close to the coast land–sea contamination seems to deteriorate the quality. Besides, spectral analysis shows that nodal sampled salinities become closer to what is geophysically expected without loss of effective spatial resolution.
Paraules clau: Soil Moisture and Ocean Salinity (SMOS) Interferometry Radiometry Image reconstruction Nodal sampling Nodal points Sidelobes Radio Frequency Interferences (RFI) Salinity retrievals
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Atienza D., A. Sabatés, S. Isari, E. Saiz, A. Calbet
Journal of Marine Systems, 164, 30-41. DOI: 10.1016/j.jmarsys.2016.08.003 (BibTeX: atienza.etal.2016)
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Isla E.,
In: Source-to-Sink Fluxes in Undisturbed Cold Environments, Ed. A.A. Beylich, J.C. Dixon, Z. Zwoliński. Cambridge University Press. Chap. 16. 199-212. ISBN: 9781107068223 (BibTeX: isla.2016c)
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Pascual M., M.G. Neubert, J.L. Acuña, A.R. Solow, C. Domínguez-Carrió, J. Salvador, A. Olariaga, V. Fuentes
Marine Ecology Progress Series, 561, 189-201. DOI: 10.3354/meps11915 (BibTeX: pascual.etal.2016c)
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Giner C.R., I. Forn, S. Romac, R. Logares, C. Vargas, R. Massana
Applied and Environmental Microbiology, 82, 15, 4757-4766. DOI: 10.1128/AEM.00560-16 (BibTeX: giner.etal.2016)
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García M., F.J. Hernández-Molina, B. Alonso, J.T. Vázquez, G. Ercilla, E. Llave, D. Casas
Marine Geology, 378, 5-19. DOI: 10.1016/j.margeo.2015.10.004 (BibTeX: garcia.etal.2016b)
Resum: Veure
Morphological features (escarpments, depressions and valleys) identified on the Guadalquivir Bank, within the middle slope of the Gulf of Cadiz, have been investigated based on high- and mid-resolution geophysical datasets. The morphological and seismic stratigraphic analyses allowed their interpretation as the result of the interaction between oceanographic, mass-wasting and tectonic processes. A phase of enhanced tectonic activity occurred during the Mid-Pleistocene related to the activity of diapiric structures, the front of the allochthonous units, and/or basement uplift or adjustments. This event seems crucial for the origin of widespread mass-wasting events along middle slope sheeted drift plateaus that have been further reworked by the Mediterranean Outflow Water. This resulted in the erosion of a marginal valley to the north of the Guadalquivir Bank, while fluid escape processes also have a minor role in the creation of crescent-shaped depressions. The Diego Cao channel is the result of a complex evolution, from a contourite moat associated to a separated drift to a multi-crested drift and moat system during the Pliocene and Early Quaternary. During the Mid-Pleistocene, the mass-wasting phase produced a prominent erosive surface that opened a deep gateway into the Guadalquivir Bank uplifted basement, allowing the onset of the Mediterranean Intermediate Branch to flow towards the N-NW. The system evolved into a contourite system composed of the present-day channel and an associated deposit on its western side (Bartolomeu Dias sheeted drift plateau) that forms a particularly complex separated drift. This drift displays a series of circular depressions that are similar in morphology to collapse features or pockmarks, but are in contrast, the result of the interaction between the bottom current and the irregular mass-wasting-related scars.
Paraules clau: Gulf of Cadiz, contourite depositional system, erosional features, morphology, seismic stratigraphy, Mediterranean Outflow Water
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Mecklenburg S., M. Drusch, L. Kaleschke, N. Rodriguez-Fernandez, N. Reul, Y. Kerr, J. Font, M. Martin-Neira, R. Oliva, E. Daganzo-Eusebio, J.P. Grant, R. Sabia, G. Macelloni, K. Rautiainen, J. Fauste, P. de Rosnay, J. Munoz-Sabater, N. Verhoest, H. Lievens, S. Delwart, R. Crapolicchio, A. de la Fuente, M. Kornberg
Remote Sensing of Environment, 180, 3-18. DOI: 10.1016/j.rse.2015.12.025 (BibTeX: mecklenburg.etal.2016c)
Resum: Veure
The Soil Moisture and Ocean Salinity (SMOS) mission, launched in November 2009, is the European Space Agency\'s (ESA) second Earth Explorer Opportunity mission. The scientific objectives of the SMOS mission directly respond to the need for global observations of soil moisture and ocean salinity, two key variables used in predictive hydrological, oceanographic and atmospheric models. SMOS observations also provide information on vegetation, in particular plant available water and water content in a canopy, drought index and flood risks, surface ocean winds in storms, freeze/thaw state and sea ice and its effect on ocean-atmosphere heat fluxes and dynamics affecting large-scale processes of the Earth\'s climate system. Significant progress has been made over the course of the now 6-year life time of the SMOS mission in improving the ESA provided level 1 brightness temperature and level 2 soil moisture and sea surface salinity data products. The main emphasis of this paper is to review the status of the mission and provide an overview and performance assessment of SMOS data products, in particular with a view towards operational applications, and using SMOS products in data assimilation. SMOS is in excellent technical condition with no limiting factors for operations beyond 2017. The instrument performance fulfils the requirements. The radio-frequency interference (RFI) contamination originates from man-made emitters on ground, operating in the protected L-band and adding signal to the natural radiation emitted by the Earth. RFI has been detected worldwide and has been significantly reduced in Europe and the Americas but remains a constraint in Asia and the Middle East. The mission\'s scientific objectives have been reached over land and are approaching the mission objectives over ocean. This review paper aims to provide an introduction and synthesis to the papers published in this RSE special issue on SMOS
Paraules clau: Soil Moisture and Ocean Salinity (SMOS) mission, Sea surface salinity, Soil moisture, Sea ice thickness, Vegetation optical depth, Severe wind tracking, Data assimilation, Hydrological forecasting, L-band radiometry, Satellite remote sensing, Freeze and thaw
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Vila M., R. Abós-Herràndiz, J. Isern-Fontanet, J. Àlvarez, E. Berdalet
Scientia Marina, 80, S1, 107-115. (BibTeX: vila.etal.2016)
Resum: Veure
Blooms of the benthic dinoflagellate Ostreopsis have been related to sporadic acute respiratory symptoms and general malaise in people exposed to marine aerosols on some Mediterranean beaches. However, the direct link between recurrent Ostreopsis blooms and health problems has not been clearly established. In order to establish and elucidate the connection, we conducted a joint ecology and epidemiology study in an Ostreopsis hot spot. Throughout the bloom, which extended from the end of June until the end of October 2013, 81% of the human cohort that we studied experienced at least one Ostreopsis-related symptom. Paradoxically, the time when the effects were greatest was during a short time window in early August. This corresponded to the transition from the exponential growth to the stationary phase of the bloom. Negligible symptoms were reported from August to mid-October, during the stationary period of the proliferation, when O. cf. ovata maintained high concentrations of epiphytic cells. No clear patterns in the landward wind component were noted during the time when health effects were greatest. Our main hypothesis is that the irritants present in the aerosol are produced during a particular physiological phase of the Ostreopsis cells during the bloom.
Paraules clau: Ostreopsis, epidemiology, Mediterranean, HAB, dinoflagellates, respiratory irritation, epidemiología, Mediterráneo, proliferaciones algales nocivas, dinoflagelados, irritaciones respiratorias
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Bardaji R., A.M. Sánchez, C. Simon, M.R. Wernand, J. Piera
Sensors, 16, 3, DOI: 10.3390/s16030373 (BibTeX: bardaji.etal.2016c)
Resum: Veure
A critical parameter to assess the environmental status of water bodies is the transparency of the water, as it is strongly affected by different water quality related components (such as the presence of phytoplankton, organic matter and sediment concentrations). One parameter to assess the water transparency is the diffuse attenuation coefficient. However, the number of subsurface irradiance measurements obtained with conventional instrumentation is relatively low, due to instrument costs and the logistic requirements to provide regular and autonomous observations. In recent years, the citizen science concept has increased the number of environmental observations, both in time and space. The recent technological advances in embedded systems and sensors also enable volunteers (citizens) to create their own devices (known as Do-It-Yourself or DIY technologies). In this paper, a DIY instrument to measure irradiance at different depths and automatically calculate the diffuse attenuation Kd coefficient is presented. The instrument, named KdUINO, is based on an encapsulated low-cost photonic sensor and Arduino (an open-hardware platform for the data acquisition). The whole instrument has been successfully operated and the data validated comparing the KdUINO measurements with the commercial instruments. Workshops have been organized with high school students to validate its feasibility.
Paraules clau: Arduino, buoy, citizen science, do-it-yourself, KdUINO, light, low-cost sensor, oceanography; diffuuse attenuation coefficient
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Aparicio F. L., M. Nieto-Cid, E. Borrull, E. Calvo, C. Pelejero, M.M. Sala, J. Pinhassi, J.M. Gasol, C. Marrasé
Science of The Total Environment, 563-564, 179-189. DOI: 10.1016/j.scitotenv.2016.04.108 (BibTeX: l.aparicio.etal.2016a)
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Ferrera I., C.R. Giner, A. Reñé, J. Camp, R. Massana, J.M. Gasol, E. Garcés
Frontiers in Marine Science, 3, 147, 1-16. DOI: 10.3389/fmars.2016.00147 (BibTeX: ferrera.etal.2016a)
Resum: Veure
Sequencing of rRNA gene polymerase chain reaction amplicons (rRNA tags) is the most common approach for investigating microbial diversity. The recent development of high-throughput sequencing (HTS) technologies has enabled the exploration of microbial biodiversity at an unprecedented scale, greatly expanding our knowledge on the microbiomes of marine ecosystems. These approaches provide accurate, fast, and cost efficient observations of the marine communities, and thus, may be suitable tools in biodiversity monitoring programs. To reach this goal, consistent and comparable methodologies must be used over time and within sites. Here, we have performed a cross-platform study of the two most common HTS methodologies, i.e., 454-pyrosequencing and Illumina tags to evaluate their usefulness in biodiversity monitoring and assessment of environmental status. Picoplankton biodiversity has been compared through both methodologies by sequencing the 16 and 18 S rRNA genes of a set of samples collected in the coast of Barcelona (NW Mediterranean). The results show that, despite differences observed in the rare OTUs retrieved, both platforms provide a comparable view of the marine picoplankton communities. On a taxonomic level, there was an accurate overlap in the detected phyla between the two methods and the overall estimates of alpha- and betadiversity were comparable. In addition, we explored the concept of “indicator species” and found that certain taxa (i.e., members of the Gammaproteobacteria among others) as well as the ratio between some phylogenetic groups (i.e., the ratio of Alphaproteobacteria/Gammaproteobacteria, Alteromonas/SAR11, and Alteromonas + Oceanospirillales/SAR11) have potential for being useful indicators of environmental status. The data show that implementing new protocols and identifying indicators of environmental status based on rRNA amplicon sequencing is feasible, and that is worth exploring whether the identified indices are universally applicable.
Paraules clau: plankton diversity, high-throughput sequencing, marine ecosystems, prokaryotes, picoplankton, monitoring programs, indicators, environmental status
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1.5 Mb
Harrison R.M., A.M. Jones, D.C.S. Beddows, M. Dall\'Osto, I. Nikolova
Atmospheric Environment, 125, 1-7. DOI: 10.1016/j.atmosenv.2015.10.077 (BibTeX: harrison.etal.2016)
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Solé M., M. Lenoir, J.M. Fortuño, M. Durfort, M. van der Schaar, M. André
Scientific Reports, 6, 37979. DOI: 10.1038/srep37979 (BibTeX: sole.etal.2016j)
Resum: Veure
Jellyfishes represent a group of species that play an important role in oceans, particularly as a food source for different taxa and as a predator of fish larvae and planktonic prey. The massive introduction of artificial sound sources in the oceans has become a concern to science and society. While we are only beginning to understand that non-hearing specialists like cephalopods can be affected by anthropogenic noises and regulation is underway to measure European water noise levels, we still don\'t know yet if the impact of sound may be extended to other lower level taxa of the food web. Here we exposed two species of Mediterranean Scyphozoan medusa, Cotylorhiza tuberculata and Rhizostoma pulmo to a sweep of low frequency sounds. Scanning electron microscopy (SEM) revealed injuries in the statocyst sensory epithelium of both species after exposure to sound, that are consistent with the manifestation of a massive acoustic trauma observed in other species. The presence of acoustic trauma in marine species that are not hearing specialists, like medusa, shows the magnitude of the problem of noise pollution and the complexity of the task to determine threshold values that would help building up regulation to prevent permanent damage of the ecosystems.
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Solé J., M. Emelianov, A. Ostrovskii, P. Puig, E. García-Ladona
Scientia Marina, 80S1, 195-204. DOI: http://dx.doi.org/10.3989/scimar.04322.05A (BibTeX: sole.etal.2016c)
Resum: Veure
In this work we report short-term measurements of the thermohaline structure and velocity field inside a narrow submarine canyon by means of a yo-yo–like profiler. An Aqualog profiler was deployed inside the Besòs Canyon in the northwestern Mediterranean continental margin, providing a unique data set on the vertical evolution of water column characteristics with unprecedented fine-scale spatial and temporal resolution. The observations reported here show a very dynamic transient short-term response with a complex vertical structure not observed previously in any submarine canyon of this region. The vertical distribution of water masses was characteristic of the western Mediterranean basin with Atlantic waters (AW) at the surface, Western Intermediate waters (WIW) in the middle and Levantine Intermediate (LIW) waters below. Turner angle and empirical orthogonal functions show that double-diffusive and isopycnal mixing are the main dominant processes at small scales. The interfaces of the three layers exhibit highly vertical excursions in relatively short times. At the surface, deepening of AW was observed, associated with flow intensification events. Deeper in the water column, within the submarine canyon confinement, the WIW-LIW interface uplifts about 100-150 m. These motions are associated with relatively up- and down-canyon–enhanced current events (up to 15-20 cm s–1 at 500 and 800 m depths) along the canyon axis. The time scales of the vertical variability were concentrated in a broad band around the semi-diurnal and local inertial frequencies within the WIW and LIW layers.
Paraules clau: fine-scale variability; submarine canyon; yo-yo like profiler; thermohaline structure; AW; WIW; LIW.
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Villasantea S., G.J. Pierce, C. Pita, C. Pazos, J.G. Rodrigues, M. Antelo, J.M. Da Rocha, J.G. Cutrín, L.C. Hastie, P. Veigak, U.R. Sumailal, M.Coll
Ecological Economics, 130, 130-138. DOI: 10.1016/j.ecolecon.2016.05.008 (BibTeX: villasantea.etal.2016b)
Resum: Veure
This paper investigates the impact of the European Union landing obligation in the Galician (North West of Spain) multispecies small-scale gillnet fishery. By combining results from semi-structured interviews with small-scale fishers and a bioeconomic model, we found that the percentage of discards for small-scale fisheries is usually low, which is consistent with general empirical observations globally but can be high when quotas are exhausted. Our results also confirm that the landing obligation would generate negative impacts on fishers\' activities by investing more time on-board to handle previously discarded fishes, and putting at risk the security of fishers at sea due to full use of allowable storage on-board coupled with often adverse sea conditions in Galician bays. The application of the landing obligation policy to small-scale fisheries would result in short- and long-term losses of fishing days and yields, with high negative impacts on sustainable fisheries such as the Galician multispecies small-scale gillnet fishery. The expected number of fishing days under the landing obligation is estimated to be reduced by 50% during the five years following the implementation of the policy. The future yield (catches) under the landing obligation would be only 50% of catches expected in the absence of the landing obligation, regardless of the total volume of quotas allocated to the fleet.
Paraules clau: Common Fisheries Policy, discard ban, fishers perceptions, economic impacts, multispecies gillnet small-scale fishery, Galicia (North West of Spain)
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Foreword (2016)
Pelegrí J.L., D. Vaqué
Scientia Marina, 80S1, 9-10. (BibTeX: pelegri.vaque.2016)
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Simó R.,
Environmental Chemistry, 13, i-iii. DOI: 10.1071/ENv13n2_FO (BibTeX: simo.2016)
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7.6 Mb
Thomsen H.A., L. Cros, E. Malinverno, J.B. Østergaard, M.Y. Cortés, M. Geisen, J.R. Young
Journal of Micropalaeontology, 35, 125-135. DOI: 10.1144/jmpaleo2015-013 (BibTeX: thomsen.etal.2016)
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1.7 Mb
Camps A., C. Gabarró, M. Vall-llossera, S. Blanch, A. Aguasca, F. Torres, I. Corbella, N. Duffo, A. Turiel, M. Portabella, J. Ballabrera-Poy, V. González-Gambau, J. Martínez, R. Villarino, L. Enrique, A. Monerris, X. Bosch, R. Sabia, M. Talone, M. Piles, M. Pablos, E. Valencia
Scientia Marina, 80, S1, 159-172. DOI: 10.3989/scimar.04285.04A (BibTeX: camps.etal.2016b)
Resum: Veure
This article summarizes some of the activities in which Jordi Font, research professor and head of the Department of Physical and Technological Oceanography, Institut de Ciències del Mar (CSIC, Spanish National Research Council) in Barcelona, has been involved as co-Principal Investigator for Ocean Salinity of the European Space Agency Soil Moisture and Ocean Salinity (SMOS) Earth Explorer Mission from the perspective of the Remote Sensing Lab at the Universitat Politècnica de Catalunya. We have probably left out some of his many contributions to salinity remote sensing, but we hope that this review will give an idea of the importance of his work. We focus on the following issues: 1) the new accurate measurements of the sea water dielectric constant, 2) the WISE and EuroSTARRS field experiments that helped to define the geophysical model function relating brightness temperature to sea state, 3) the FROG 2003 field experiment that helped to understand the emission of sea foam, 4) GNSS-R techniques for improving sea surface salinity retrieval, 5) instrument characterization campaigns, and 6) the operational implementation of the Processing Centre of Levels 3 and 4 at the SMOS Barcelona Expert Centre.
Paraules clau: SMOS, radiometry, interferometry, calibration, validation, salinity, soil moisture, sea ice, GNSS-R, radiometría, interferometría, calibración, validación, salinidad, humedad del terreno, hielo marino
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3.2 Mb
Weisse T., R. Anderson, H. Arndt, A. Calbet, P.J. Hansen, D.J.S. Montagnes
European Journal of Protistology, 55, A, 50-74. DOI: 10.1016/j.ejop.2016.03.003 (BibTeX: weisse.etal.2016)
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1.4 Mb
Fuentes V., G. Alurralde, B. Meyer, G.E. Aguirre, A. Canepa, A.C. Wölfl, H.C. Hass, G.N. Williams, I.R. Schloss
Scientific Reports, 6, 27234, 1-12. DOI: 10.1038/srep27234 (BibTeX: fuentes.etal.2016)
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2.6 Mb
Cabello A.M., F.M. Cornejo-Castillo, N. Raho, D. Blasco, M. Vidal, S. Audic, C. de Vargas, M. Latasa, S.G. Acinas, R. Massana
ISME Journal, 10, 693-706. DOI: 10.1038/ismej.2015.147 (BibTeX: cabello.etal.2016a)
Resum: Veure
A marine symbiosis has been recently discovered between prymnesiophyte species and the unicellular diazotrophic cyanobacterium UCYN-A. At least two different UCYN-A phylotypes exist, the clade UCYN-A1 in symbiosis with an uncultured small prymnesiophyte and the clade UCYN-A2 in symbiosis with the larger Braarudosphaera bigelowii. We targeted the prymnesiophyte–UCYN-A1 symbiosis by double CARD-FISH (catalyzed reporter deposition-fluorescence in situ hybridization) and analyzed its abundance in surface samples from the MALASPINA circumnavigation expedition. Our use of a specific probe for the prymnesiophyte partner allowed us to verify that this algal species virtually always carried the UCYN-A symbiont, indicating that the association was also obligate for the host. The prymnesiophyte–UCYN-A1 symbiosis was detected in all ocean basins, displaying a patchy distribution with abundances (up to 500 cells ml−1) that could vary orders of magnitude. Additional vertical profiles taken at the NE Atlantic showed that this symbiosis occupied the upper water column and disappeared towards the Deep Chlorophyll Maximum, where the biomass of the prymnesiophyte assemblage peaked. Moreover, sequences of both prymnesiophyte partners were searched within a large 18S rDNA metabarcoding data set from the Tara-Oceans expedition around the world. This sequence-based analysis supported the patchy distribution of the UCYN-A1 host observed by CARD-FISH and highlighted an unexpected homogeneous distribution (at low relative abundance) of B. bigelowii in the open ocean. Our results demonstrate that partners are always in symbiosis in nature and show contrasted ecological patterns of the two related lineages.
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Salazar G., F.M. Cornejo-Castillo, V. Benítez-Barrios, E. Fraile-Nuez, X.A. Álvarez-Salgado, C.M. Duarte, J.M. Gasol, S.G. Acinas
ISME Journal, 10, 596–608. DOI: 10.1038/ismej.2015.137 (BibTeX: salazar.etal.2016b)
Resum: Veure
The deep-sea is the largest biome of the biosphere, and contains more than half of the whole ocean’s microbes. Uncovering their general patterns of diversity and community structure at a global scale remains a great challenge, as only fragmentary information of deep-sea microbial diversity exists based on regional-scale studies. Here we report the first globally comprehensive survey of the prokaryotic communities inhabiting the bathypelagic ocean using high-throughput sequencing of the 16S rRNA gene. This work identifies the dominant prokaryotes in the pelagic deep ocean and reveals that 50% of the operational taxonomic units (OTUs) belong to previously unknown prokaryotic taxa, most of which are rare and appear in just a few samples. We show that whereas the local richness of communities is comparable to that observed in previous regional studies, the global pool of prokaryotic taxa detected is modest (~3600 OTUs), as a high proportion of OTUs are shared among samples. The water masses appear to act as clear drivers of the geographical distribution of both particle-attached and free-living prokaryotes. In addition, we show that the deep-oceanic basins in which the bathypelagic realm is divided contain different particle-attached (but not free-living) microbial communities. The combination of the aging of the water masses and a lack of complete dispersal are identified as the main drivers for this biogeographical pattern. All together, we identify the potential of the deep ocean as a reservoir of still unknown biological diversity with a higher degree of spatial complexity than hitherto considered.
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Yelton A.P., S.G. Acinas, S. Sunagawa, P. Bork, C. Pedrós-Alió, S.W. Chisholm
ISME Journal, 10, 2946-2957. DOI: 10.1038/ismej.2016.64 (BibTeX: yelton.etal.2016)
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Gutt J., B. David, E. Isla, D. Piepenburg
Polar Biology, 39, 5, 761-764. DOI: 10.1007/s00300-016-1937-7 (BibTeX: gutt.etal.2016c)
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Glynn F., J.D.R. Houghton, T. Bastian, T.K. Doyle, V. Fuentes, M.K.S. Lilley, J. Provan
Biological Journal of the Linnean Society, 117, 2, 252-263. DOI: 10.1111/bij.12654 (BibTeX: glynn.etal.2016)
Resum: Veure
Despite the importance of gelatinous zooplankton as components of marine ecosystems, both ecologically and socio-economically, relatively little information is known about population persistence or connectivity in jellyfish. In the present study, we employed a combination of nuclear microsatellite markers and sequence data from the mitochondrial cytochrome oxidase I (COI) gene to determine levels and patterns of population genetic structuring in the holoplanktonic jellyfish Pelagia noctiluca across the northeast Atlantic Ocean and Mediterranean Sea. Our results indicate a high degree of connectivity in P. noctiluca, with little evidence of geographical structuring of genetic variation. A small but significant differentiation of Atlantic Ocean and Mediterranean stocks was detected based on the microsatellite data, but no evidence of differentiation was observed with the mtDNA, probably due to the higher power of the microsatellites to detect low levels of genetic structuring. Two clearly distinct groups of genotypes were observed within the mtDNA COI, which probably diverged in the early Pleistocene, but with no evidence of geographical structuring. Palaeodistribution modelling of P. noctiluca at the Last Glacial Maximum (LGM; c. 21 Kya) indicated large areas of suitable habitat south of the species’ current-day distribution, with little reduction in area. The congruent evidence for minimal genetic differentiation from the nuclear microsatellites and the mtDNA, coupled with the results of the palaeodistribution modelling, supports the idea of long-term population stability and connectivity, thus providing key insights into the population dynamics and demography of this important species.
Paraules clau: gelatinous zooplankton, microsatellites, mitochondrial COI, palaeodistribution modelling, population genetics
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1.2 Mb
Guerrero E., A. Marrodán, A. Sabatés, C. Orejas, J.M. Gili
Scientia Marina, 80, 4, 487-497. DOI: 10.3989/scimar.04452.03A (BibTeX: guerrero.etal.2016)
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Neves M.C., C. Roque, K.M. Luttrell, J.T. Vázquez, B. Alonso
Geo-Marine Letters, 36, 6, 415 -424. DOI: 10.1007/s00367-016-0459-1 (BibTeX: neves.etal.2016b)
Resum: Veure
Earthquakes and submarine landslides are recurrent and widespread manifestations of fault activity offshore SW Iberia. The present work tests the effects of sea-level rise on offshore fault systems using Coulomb stress change calculations across the Alentejo margin. Large-scale faults capable of generating large earthquakes and tsunamis in the region, especially NE–SW trending thrusts and WNW–ESE trending dextral strike-slip faults imaged at basement depths, are either blocked or unaffected by flexural effects related to sea-level changes. Large-magnitude earthquakes occurring along these structures may, therefore, be less frequent during periods of sea-level rise. In contrast, sea-level rise promotes shallow fault ruptures within the sedimentary sequence along the continental slope and upper rise within distances of <100 km from the coast. The results suggest that the occurrence of continental slope failures may either increase (if triggered by shallow fault ruptures) or decrease (if triggered by deep fault ruptures) as a result of sea-level rise. Moreover, observations of slope failures affecting the area of the Sines contourite drift highlight the role of sediment properties as preconditioning factors in this region.
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Danovaro R., L. Carugati, M. Berzano, A.E. Cahill, S. Carvalho, A. Chenuil, C. Corinaldesi, S. Cristina, R.R. David, A. Dell’Anno, N. Dzhembekova, E. Garcés, J.M. Gasol, P. Goela, J.P. Feral, I. Ferrera, R. Forster, A.A. Kurekin, E. Rastelli, V. Marinova, P.I. Miller, S. Moncheva, A. Newton, J.K. Pearman, S.G. Pitois, A. Reñé, N. Rodríguez-Ezpeleta, V. Saggiomo, S.G.H. Simis, K. Stefanova, C. Wilson, M.L. Martiere, S. Greco, S. Cochrane, A. Borja
Frontiers in Marine Science, 3, 213, 1-25. DOI: 10.3389/fmars.2016.00213 (BibTeX: danovaro.etal.2016b)
Resum: Veure
Marine environmental monitoring has tended to focus on site-specific methods of investigation. These traditional methods have low spatial and temporal resolution and are relatively labor intensive per unit area/time that they cover. To implement the Marine Strategy Framework Directive (MSFD), European Member States are required to improve marine monitoring and design monitoring networks. This can be achieved by developing and testing innovative and cost-effective monitoring systems, as well as indicators of environmental status. Here, we present several recently developed methodologies and technologies to improve marine biodiversity indicators and monitoring methods. The innovative tools are discussed concerning the technologies presently utilized as well as the advantages and disadvantages of their use in routine monitoring. In particular, the present analysis focuses on: (i) molecular approaches, including microarray, Real Time quantitative PCR (qPCR), and metagenetic (metabarcoding) tools; (ii) optical (remote) sensing and acoustic methods; and (iii) in situ monitoring instruments. We also discuss their applications in marine monitoring within the MSFD through the analysis of case studies in order to evaluate their potential utilization in future routine marine monitoring. We show that these recently-developed technologies can present clear advantages in accuracy, efficiency and cost.
Paraules clau: marine monitoring, marine strategy framework directive, marine biodiversity, molecular approaches, in situ monitoring
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Olmedo E., J. Martínez, M. Umbert, N. Hoareau, M. Portabella, J. Ballabrera, A. Turiel
Remote Sensing of Environment, 180, 246-263. DOI: 10.1016/j.rse.2016.02.038 (BibTeX: olmedo.etal.2016e)
Resum: Veure
The multifractal fusion is a non-parametric technique that merges remotely-sensed maps of different ocean variables to produce higher quality remote sensing products. This method was first introduced to reduce the noise level in a map of a given ocean variable provided that a higher-quality map of a second ocean variable is available. In this work, we go one step further in both the the oretical justification and the application of the multifractal fusion. In the first part of the paper we explore if the quality of the derived maps can be improved by using a higher-dimensional tensor relating the gradient of one variable with that of the other. Higherdimension tensors require the introduction of appropriate integration schemes to avoid inducing long-range artifacts, something that is not completely solved yet. The results show that although higher-dimension tensors lead to an improvement in the spatial consistency of the derived maps (i.e., a higher quality of the associated singularity exponents), the comparisonwith in situ data still showsignificant reconstruction errors as compared to the simplified scalar approach. In the second part of the paperwe have used the scalar approach to increase the spatial and temporal resolution of the current SoilMoisture and Ocean Salinity (SMOS) Level 3 sea surface salinity (SSS)maps produced at the Barcelona Expert Center (BEC). As such, new daily SMOS SSS globalmaps are generated at a 0.05°×0.05° grid resolution. The quality of the resulting products has been assessed using in-situ comparison, singularity analysis and power density spectra. It is concluded that the multifractal fusion can be used to significantly increase the spatial and temporal resolution of the SSS maps.
Paraules clau: Remote sensing Data fusion Data merging Physical oceanography Singularity analysis Multifractal SMOS SSS
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Latasa M., A. Gutiérrez-Rodríguez, A.M. Cabello, R. Scharek
Scientia Marina, 80, S1, 57-62. DOI: 10.3989/scimar.04316.01A (BibTeX: latasa.etal.2016a)
Resum: Veure
Ecological traits of phytoplankton are being incorporated into models to better understand the dynamics of marine ecosystems and to predict their response to global change. We have compared the distribution of major phytoplankton groups in two different systems: in surface waters of the NW Mediterranean during key ecological periods, and in the DCM (deep chlorophyll maximum) formed in summer in the temperate NE Atlantic. This comparison disentangled the influence of light and nutrients on the relative position of diatoms, dinoflagellates, prymnesiophytes, pelagophytes, chlorophytes, Synechococcus and Prochlorococcus in these environments. Three clusters formed according to their affinity for nutrients: diatoms, chlorophytes and dinoflagellates as the most eutrophic groups; Synechococcus, pelagophytes and prymnesiophytes as mesotrophic groups; and Prochlorococcus as an oligotrophic group. In terms of irradiance, the phytoplankton groups did not cluster clearly. Comparing the nutrient and light preferences of the groups with their distribution in the DCM, dinoflagellates and chlorophytes appear as the most stressed, i.e. their position was most distant from their optimal light and nutrient conditions. Diatoms stayed in deeper than optimal irradiance layers, probably to meet their high nutrient requirements. On the opposite side, low nutrient requirements allowed Prochlorococcus to remain in the uppermost part of the DCM layer. The slight sub-optimal position of Synechococcus and prymnesiophytes with regard to their nutrient requirements suggests that their need for high irradiance plays a significant role in their location within the DCM. Finally, pelagophytes remained in deep layers without an apparent need for the high nutrient concentrations at those depths.
Paraules clau: Marine phytoplankton groups, ecological traits, irradiance, nutrients, deep chlorophyll maximum, grupos de fitoplancton marino, rasgos ecológicos, irradiancia, nutrientes, máximo profundo de clorofila
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Ferrera I., O. Sánchez
Biotechnology Advances, 34, 5, 790-802. DOI: 10.1016/j.biotechadv.2016.04.003 (BibTeX: ferrera.sanchez.2016)
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3.8 Mb
Morganti T.M.,
PhD thesis. Director/es: R. Coma Bau, M. Ribes Llordés. (BibTeX: morganti.2016a)
Resum: Veure
Sponges play important roles in the functioning of marine ecosystem in which they are abundant. These roles range from stabilizers of substrate, to acting as major link between benthic and pelagic realms by filtering large quantities of water and retaining the particles with high efficiency. Despite sponges have been the focus of much interest in the past years our knowledge on sponge physiology is still poorly understood. This study focused on ecophysiology of five of the most prominent sponge species dwelling the coralligenous community in the NW Mediterranea Sea, and employed an energetic approach to understanding the complex interactions between physiological constrains and seasonal fluctuations of environmental factors experienced by the organism under natural conditions. In this thesis, we contributed to the still limited knowledge of energetic mechanisms that regulate seasonal dynamics and elucidated divergent metabolic profiles between high microbial (HMA) and low microbial (LMA) abundance species accordingly to their different adaptive life strategies. For this purpose we examined the in situ feeding, filtering and respiration activity over annual cycle. Firstly, we started by developing a system for quantifying the particulate and dissolved compounds processed by sponges under natural conditions. In terms of feeding, we observed that all species retained plankton at high efficiency and DOC was the main source of carbon. However, the nitrogen fluxes showed a markedly different trophic niche between the two groups: HMA species mostly rely on dissolved compound as main source of N, while LMA solely rely on particulate fractions. Interestingly, natural variation of sponge pump did not follow natural temperature changes. During the period of maximum temperature the sponge pump did not reach its maximum values, suggesting that intrinsic mechanism as a decrease in choanocytes during reproductive cycle may regulate this metabolic process. On the other hand respiration clearly showed a seasonal pattern following natural temperature fluctuation. Combined, these results allowed us to estimate the overall energy budget, which appeared to be regulated by an increase of energy demand in summer as well as the availability of dissolved organic carbon fraction in the water column. Our result also showed different limited energetic profiles between HMA and LMA species accordingly to their different feeding strategies. LMA species appeared to procure sufficient energy to meet metabolic requirements for maintenance and growth by filtering suspended particulates, and dissolved fraction represented an additional input of carbon when available. On the contrary the heterotrophic nutrition in the natural environment may be insufficient to meet basal metabolic requirements in HMA species, suggesting other metabolic pathways as relevant for the energy budget of these species.
Paraules clau: benthic ecology, nutrient fluxes, energetic metabolism, eco-physiology, feeding acgivity, pumping and respiration rates
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Machín F.J., J.L. Pelegrí
Scientia Marina, 80S1, 205-214. DOI: 10.3989/scimar.04289.06A (BibTeX: machin.pelegri.2016b)
Resum: Veure
Mediterranean Water lenses (meddies) in the eastern North Atlantic, north of the Canary Islands, appear to often have their salty and nutrient-poor core accompanied by relatively fresh and nutrient-rich waters on top. We describe several occurrences of freshwater halos and berets for meddies sampled north of the Canary Islands—with instrumented moorings, Argo floats and oceanographic cruises—and identify the source of these fresh anomalies as diluted Antarctic Intermediate Water (AAIW). We propose that this capping takes place off Northwest Africa, as the southward-advected meddy interacts with the northward-advected AAIW. This interpretation is consistent with a simple analysis of the relevant advective-diffusive time scales associated with the passage of meddies under a layer of AAIW, and suggests that meddies may be a mechanism for AAIW export far into the North Atlantic Ocean.
Paraules clau: meddies; Antarctic Intermediate Water; eastern North Atlantic.
Intrinsic and environmental influences on DNA methylation and gene expression in fish (2016)
Anastasiadi D.,
PhD thesis. Director/es: F. Piferrer Circuns. Barcelona. (BibTeX: anastasiadi.2016a)
Resum: Veure
Epigenetic mechanisms, influenced by intrinsic and environmental factors are crucial for the regulation of gene expression and, ultimately, the phenotype. The European sea bass is used as a model to study these influences on DNA methylation and the phenotype during early development and later in life. We identify loci altered with age, suggestive of the existence of a piscine epigenetic clock. We show that moderate early developmental temperature increases are associated with genome-wide changes in DNA methylation and with parent-specific responses of genes involved in sexual development. Furthermore, we highlight a genome-wide inverse relationship of gene expression with the DNA methylation of the first intron. Lastly, we provide one of the first empirical demonstrations in support of the neural crest cell deficit hypothesis to explain Darwin’s domestication syndrome. Together, these results constitute the most integrative analysis of DNA methylation patterns in a fish species under intrinsic and ecologically relevant contexts
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Gili J.M., R. Zapata-Guardiola, E. Isla, D. Vaqué, A. Barbosa, L. Gracia-Sancho, A. Quesada
Polar Biology, 39, 1-10. DOI: 10.1007/s00300-015-1852-3. (BibTeX: gili.etal.2016a)
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Bosch-Belmar M., C. M’Rabet, R. Dhaouadi, M. Chalghaf, M.N.D. Yahia, V. Fuentes, S. Piraino, O.K.D. Yahia
Plos One. Open acces, 11, 4, 1-11. DOI: 10.1371/journal.pone.0154239 (BibTeX: boschbelmar.etal.2016)
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Emelianov M., A. Cruzado, M.P. Olivar, J. Lleonart
Scientia Marina, 80S1, 25-29. (BibTeX: emelianov.etal.2016a)
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Isari S., S. Zervoudaki, J. Peters, G. Papantoniou, C. Pelejero, E. Saiz
ICES Journal of Marine Science, 73, 3, 650-658. DOI: 10.1093/icesjms/fsv078 (BibTeX: isari.etal.2016a)
Resum: Veure
Rising levels of atmospheric CO2 are responsible for a change in the carbonate chemistry of seawater with associated pH drops (acidification) projected to reach 0.4 units from 1950 to 2100. We investigated possible indirect effects of seawater acidification on the feeding, fecundity, and hatching success of the calanoid copepod Acartia grani, mediated by potential CO2-induced changes in the nutritional characteristics of their prey. We used as prey the autotrophic dinoflagellate Heterocapsa sp., cultured at three distinct pH levels (control: 8.17, medium: 7.96, and low: 7.75) by bubbling pure CO2 via a computer automated system. Acartia grani adults collected from a laboratory culture were acclimatized for 3 d at food suspensions of Heterocapsa from each pH treatment (ca. 500 cells ml−1; 300 μg C l−1). Feeding and egg production rates of the preconditioned females did not differ significantly among the three Heterocapsa diets. Egg hatching success, monitored once per day for the 72 h, did not reveal significant difference among treatments. These results are in agreement with the lack of difference in the cellular stoichiometry (C : N, C : P, and N : P ratios) and fatty acid concentration and composition encountered between the three tested Heterocapsa treatments. Our findings disagree with those of other studies using distinct types of prey, suggesting that this kind of indirect influence of acidification on copepods may be largely associated with interspecific differences among prey items with regard to their sensitivity to elevated CO2 levels.
Paraules clau: Acartia grani, bottom-up, copepods, dinoflagellates, food quality, Heterocapsa, ocean acidification, pH
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Gallisai R., G. Volpe, F. Peters
Global Biogeochemical Cycles, 30, 1725-1737. DOI: 10.1002/2016GB005404 (BibTeX: gallisai.etal.2016a)
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Pernice M.C., C.R. Giner, R. Logares, J. Perera, S.G. Acinas, C.M. Duarte, J.M. Gasol, R. Massana
ISME Journal, 10, 945-958. DOI: 10.1038/ismej.2015.170 (BibTeX: pernice.etal.2016a)
Resum: Veure
In this work, we study the diversity of bathypelagic microbial eukaryotes (0.8–20 μm) in the global ocean. Seawater samples from 3000 to 4000 m depth from 27 stations in the Atlantic, Pacific and Indian Oceans were analyzed by pyrosequencing the V4 region of the 18S ribosomal DNA. The relative abundance of the most abundant operational taxonomic units agreed with the results of a parallel metagenomic analysis, suggesting limited PCR biases in the tag approach. Although rarefaction curves for single stations were seldom saturated, the global analysis of all sequences together suggested an adequate recovery of bathypelagic diversity. Community composition presented a large variability among samples, which was poorly explained by linear geographic distance. In fact, the similarity between communities was better explained by water mass composition (26% of the variability) and the ratio in cell abundance between prokaryotes and microbial eukaryotes (21%). Deep diversity appeared dominated by four taxonomic groups (Collodaria, Chrysophytes, Basidiomycota and MALV-II) appearing in different proportions in each sample. Novel diversity amounted to 1% of the pyrotags and was lower than expected. Our study represents an essential step in the investigation of bathypelagic microbial eukaryotes, indicating dominating taxonomic groups and suggesting idiosyncratic assemblages in distinct oceanic regions.
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Bordehore C., C. Alonso, L. Sánchez-Fernández, A. Canepa, M. Acevedo, S. Nogué, V.L. Fuentes
Ocean & Coastal Management, 131, 45-52. DOI: 10.1016/j.ocecoaman.2016.08.008 (BibTeX: bordehore.etal.2016)
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Sebastián ., M., Smith, A.F., González, J.M., Fredricks, H.F., Van Mooy, B., Koblí_ek, M., Brandsma, J., Koster, G., Mestre, M., Behzad, M., Pitta, P., Postle, A.D., Sánchez, P., Gasol, J.M., Scanlan, D.J., Chen, Y.
ISME Journal, 10, 968-978. DOI: 10.1038/ismej.2015.172 (BibTeX: .etal.2016b)
Resum: Veure
Upon phosphorus (P) deficiency, marine phytoplankton reduce their requirements for P by replacing membrane phospholipids with alternative non-phosphorus lipids. It was very recently demonstrated that a SAR11 isolate also shares this capability when phosphate starved in culture. Yet, the extent to which this process occurs in other marine heterotrophic bacteria and in the natural environment is unknown. Here, we demonstrate that the substitution of membrane phospholipids for a variety of non-phosphorus lipids is a conserved response to P deficiency among phylogenetically diverse marine heterotrophic bacteria, including members of the Alphaproteobacteria and Flavobacteria. By deletion mutagenesis and complementation in the model marine bacterium Phaeobacter sp. MED193 and heterologous expression in recombinant Escherichia coli, we confirm the roles of a phospholipase C (PlcP) and a glycosyltransferase in lipid remodelling. Analyses of the Global Ocean Sampling and Tara Oceans metagenome data sets demonstrate that PlcP is particularly abundant in areas characterized by low phosphate concentrations. Furthermore, we show that lipid remodelling occurs seasonally and responds to changing nutrient conditions in natural microbial communities from the Mediterranean Sea. Together, our results point to the key role of lipid substitution as an adaptive strategy enabling heterotrophic bacteria to thrive in the vast P-depleted areas of the ocean.
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Fanelli E., J.E. Cartes, V. Papiol, C. López-Pérez, M. Carrassón
Climate research, 67, 3, 191-207. DOI: 10.3354/cr01369 (BibTeX: fanelli.etal.2016a)
Resum: Veure
Although the deep sea is considered a relatively stable environment, it is affected by climatic and environmental variations with implications for functioning of its ecosystems and food webs. We used stable isotopes to compare trophic levels of 21 species of deep-sea megafauna (fish, decapods and other invertebrates) between 2 periods separated by ca. 20 yr (1985-1989 vs. 2007-2011) and characterized by different climatic conditions (based on the NAO index), by increases in temperature and salinity and by a decrease in O2 concentration in intermediate (Levantine Intermediate Waters, LIW) and deep (at the Benthic Boundary Layer, BBL) water masses in the Balearic Basin. We found a decrease in the δ15N of benthopelagic fishes (1.5‰ on average), benthic invertebrates (1.1‰) and pelagic organisms (0.8‰) from 1985-1989 to 2007-2011, a temporal decline confirmed with additional analyses performed after compiling published data collected in 1996, 1998, 2003/2004 and 2007/2008 from the same area. Changes in trophic levels (based on δ15N) were correlated (Spearman’s R) to temperature increase, i.e. species seemed to feed on lower trophic levels during warmer periods. According to generalized linear models, the main explanatory variables for changes in δ15N were O2 in the BBL and at the core of the LIW, chlorophyll a concentration at the surface and salinity near the bottom. We hypothesize that the changes in oceanographic conditions in the Mediterranean, driven by both global change and river damming, have influenced benthic organisms by reducing their biomass and/or size, shifting megafauna (mainly fish) to feed on more pelagic or smaller benthic prey, with lower δ15N values, in 2007-2011 compared to 1985-1989
Paraules clau: Climate change, temperature increase, deep-sea communities, Western Mediterranean
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González-Zamora Á., N. Sánchez, J. Martínez-Fernández, A. Gumuzzio, M. Piles, E. Olmedo
Physics and Chemistry of the Earth, Parts A/B/C, 83-84, 123-136. DOI: http://dx.doi.org/10.1016/j.pce.2015.05.009 (BibTeX: gonzalezzamora.etal.2016)
Resum: Veure
The European Space Agency’s Soil Moisture and Ocean Salinity (SMOS) Level 2 soil moisture and the new L3 product from the Barcelona Expert Center (BEC) were validated from January 2010 to June 2014 using two in situ networks in Spain. The first network is the Soil Moisture Measurement Stations Network of the University of Salamanca (REMEDHUS), which has been extensively used for validating remotely sensed observations of soil moisture. REMEDHUS can be considered a small-scale network that covers a 1300 km2 region. The second network is a large-scale network that covers the main part of the Duero Basin (65,000 km2). At an existing meteorological network in the Castilla y Leon region (Inforiego), soil moisture probes were installed in 2012 to provide data until 2014. Comparisons of the temporal series using different strategies (total average, land use, and soil type) as well as using the collocated data at each location were performed. Additionally, spatial correlations on each date were computed for specific days. Finally, an improved version of the Triple Collocation (TC) method, i.e., the Extended Triple Collocation (ETC), was used to compare satellite and in situ soil moisture estimates with outputs of the Soil Water Balance Model Green-Ampt (SWBM-GA). The results of this work showed that SMOS estimates were consistent with in situ measurements in the time series comparisons, with Pearson correlation coefficients (R) and an Agreement Index (AI) higher than 0.8 for the total average and the land-use averages and higher than 0.85 for the soil-texture averages. The results obtained at the Inforiego network showed slightly better results than REMEDHUS, which may be related to the larger scale of the former network. Moreover, the best results were obtained when all networks were jointly considered. In contrast, the spatial matching produced worse results for all the cases studied. These results showed that the recent reprocessing of the L2 products (v5.51) improved the accuracy of soil moisture retrievals such that they are now suitable for developing new L3 products, such as the presented in this work. Additionally, the validation based on comparisons between dense/sparse networks and satellite retrievals at a coarse resolution showed that temporal patterns in the soil moisture are better reproduced than spatial patterns.
Paraules clau: SMOS; Soil moisture; Validation; Extended Triple Collocation; Hydrological modeling
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Casas D., F. Chiocci, D. Casalbore, G. Ercilla, J. Ortiz de Urbina
Geo-Marine Letters, 36, 6, 405-414. DOI: 10.1007/s00367-016-0458-2 (BibTeX: casas.etal.2016b)
Resum: Veure
Regional inventories and magnitude-frequency relationships provide critical information about landslides and represent a first step in landslide hazard assessment. Despite this, the availability of accurate inventories in the marine environment remains poor because of the commonly low accessibility of high-resolution data at regional scales. Evaluating high-resolution bathymetric data spanning the time interval 2007–2011 for the Gioa Basin of the southern Tyrrhenian Sea yielded a landslide inventory of 428 events affecting an area of >85 km2 and mobilizing approximately 1.4 km3 of sediment. This is the first time that this area is studied in such detail, justifying comparison with other areas both onland and offshore. Statistical analyses revealed that the cumulative distribution of the dataset is characterized by two right-skewed probability distributions with a heavy tail. Moreover, evidence of a rollover for smaller landslide volumes is consistent with similar trends reported in other settings worldwide. This may reflect an observational limitation and the site-specific geologic factors that influence landslide occurrence. The robust validation of both power-law and log-normal probability distributions enables the quantification of a range of probabilities for new extreme events far from the background landslide sizes defined in the area. This is a useful tool at regional scales, especially in geologically active areas where submarine landslides can occur frequently, such as the Gioia Basin.
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Baltar F., J. Palovaara, F. Unrein, P. Catala, K. Hornak, D. Vaqué, R. Massana, J.M. Gasol, J. Pinhassi
ISME Journal, 10, 3, 568-581. DOI: 10.1038/ismej.2015.135 (BibTeX: baltar.etal.2016a)
Resum: Veure
To test whether protist grazing selectively affects the composition of aquatic bacterial communities, we combined high-throughput sequencing to determine bacterial community composition with analyses of grazing rates, protist and bacterial abundances and bacterial cell sizes and physiological states in a mesocosm experiment in which nutrients were added to stimulate a phytoplankton bloom. A large variability was observed in the abundances of bacteria (from 0.7 to 2.4 × 106 cells per ml), heterotrophic nanoflagellates (from 0.063 to 2.7 × 104 cells per ml) and ciliates (from 100 to 3000 cells per l) during the experiment (~3-, 45- and 30-fold, respectively), as well as in bulk grazing rates (from 1 to 13 × 106 bacteria per ml per day) and bacterial production (from 3 to 379 μg per C l per day) (1 and 2 orders of magnitude, respectively). However, these strong changes in predation pressure did not induce comparable responses in bacterial community composition, indicating that bacterial community structure was resilient to changes in protist predation pressure. Overall, our results indicate that peaks in protist predation (at least those associated with phytoplankton blooms) do not necessarily trigger substantial changes in the composition of coastal marine bacterioplankton communities.
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Berdalet E., L.E. Fleming, R. Gowen, K. Davidson, P. Hess, L.C. Backer, S.K. Moore, P. Hoagland, H. Enevoldsen
Journal of the Marine Biological Association of the United Kingdom, 96, 1, 61-91. DOI: 10.1017/S0025315415001733 (BibTeX: berdalet.etal.2016a)
Resum: Veure
Microalgal blooms are a natural part of the seasonal cycle of photosynthetic organisms in marine ecosystems. They are key components of the structure and dynamics of the oceans and thus sustain the benefits that humans obtain from these aquatic environments. However, some microalgal blooms can cause harm to humans and other organisms. These harmful algal blooms (HABs) have direct impacts on human health and negative influences on human wellbeing, mainly through their consequences to coastal ecosystem services (fisheries, tourism and recreation) and other marine organisms and environments. HABs are natural phenomena, but these events can be favoured by anthropogenic pressures in coastal areas. Global warming and associated changes in the oceans could affect HAB occurrences and toxicity as well, although forecasting the possible trends is still speculative and requires intensive multidisciplinary research. At the beginning of the 21st century, with expanding human populations, particularly in coastal and developing countries, mitigating HABs impacts on human health and wellbeing is becoming a more pressing public health need. The available tools to address this global challenge include maintaining intensive, multidisciplinary and collaborative scientific research, and strengthening the coordination with stakeholders, policymakers and the general public. Here we provide an overview of different aspects of the HABs phenomena, an important element of the intrinsic links between oceans and human health and wellbeing.
Paraules clau: Harmful algal blooms, human health and wellbeing, marine biotoxins, ecosystem services
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Cabello Pérez A.M.,
PhD thesis. Director/es: M. Latasa, R. Massana. Las Palmas de Gran Canaria. (BibTeX: cabelloperez.2016h)
Resum: Veure
Marine photosynthetic picoeukaryotes or PPEs, single-celled algae from 0.8 to 3 µm in size, are major contributors to phytoplankton biomass and primary production in marine systems and form diverse communities dominated by prymnesiophytes, chlorophytes, pelagophytes, and chrysophytes. Due to their ecological relevance it is important to characterize PPE community structure over temporal and spatial scales and to identify the environmental factors shaping community assembly. In this thesis we focused on major PPE groups, with the aim of determining.
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Cermeño P., P. Chouciño, B. Fernández-Castro, F.G. Figueiras, E. Marañón, C. Marrasé, B. Mouriño-Carballido, M. Pérez-Lorenzo, T. Rodríguez-Ramos, I.G. Teixeira, S.M. Vallina
Frontiers in Marine Science, 3, 173, 1-10. DOI: 10.3389/fmars.2016.00173 (BibTeX: cermeno.etal.2016)
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Sánchez A.M., J. Piera
Biogeosciences, 13, 4081-4098. DOI: 10.5194/bg-13-4081-2016 (BibTeX: sanchez.piera.2016b)
Resum: Veure
The scattering properties of aquatic suspended particles have many optical applications. Several data inversion methods have been proposed to estimate important features of particles, such as their size distribution or their refractive index. Most of the proposed methods are based on the Lorenz–Mie theory to solve Maxwell\'s equations, where particles are considered homogeneous spheres. A generalization that allows consideration of more complex-shaped particles is the T-matrix method. Although this approach imposes some geometrical restrictions (particles must be rotationally symmetrical) it is applicable to many life forms of phytoplankton. In this paper, three different scenarios are considered in order to compare the performance of several inversion methods for retrieving refractive indices. The error associated with each method is discussed and analyzed. The results suggest that inverse methods using the T-matrix approach are useful to accurately retrieve the refractive indices of particles with complex shapes, such as for many phytoplankton organisms.
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Schiaffino M.R., E. Lara, L.D. Fernández, V. Balagué, D. Singer, C.C.W. Seppey, R. Massana, I. Izaguirre
Environmental Microbiology, 18, 12, 5249-5264. DOI: 10.1111/1462-2920.13566 (BibTeX: schiaffino.etal.2016b)
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Masó M., J.-M. Fortuño, S. de Juan, M. Demestre
Scientia Marina, 80, S1, 117-127. DOI: 10.3989/scimar.04281.10A (BibTeX: maso.etal.2016a)
Resum: Veure
The present study used scanning electron microscopy to characterize the organisms colonizing marine plastic debris collected from pelagic and benthic habitats across Mediterranean coastal waters of Greece, Italy and Spain. A total of 42 fragments of plastic were collected during the COMSOM experimental cruise, 16 from the seafloor and 26 from surface waters. The results showed that diatoms were the most abundant organisms on both pelagic and benthic plastics. The diatom Ceratoneis closterium, frequently observed on surface plastics (73%), is a harmful microalgae associated with mucilage events in the Mediterranean. The abundance of marine plastic in coastal and oceanic waters may provide new habitats that offer an easy substrate for these invasive organisms. Furthermore, the colonization of these new environments might reduce the success of life strategies, or drive the organisms out of their essential habitat by dispersion and rafting phenomena. The results of the present work highlight the need to increase our knowledge of the consequences of colonization of plastics introduced into the marine environment, and the need to raise awareness of the potential impacts of debris accumulation on biodiversity of marine ecosystems.
Paraules clau: Scanning electron microscope, marine plastic debris, biofouling, northern Mediterranean Sea, microscopio electrónico de barrido, basura de plásticos marinos, biofouling, norte del mar Mediterráneo
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Jewson D., A. Kuwata, Ll. Cros, J.-M. Fortuño, M. Estrada
Scientia Marina, 80, S1, 89-96. DOI: 10.3989/scimar.04331.06C (BibTeX: jewson.etal.2016a)
Resum: Veure
Minidiscus comicus is a marine centric diatom that has cells with diameters as small as 1.9 μm, which brings it close to the lower limit of diatom cell size and also near to the lower limit of photosynthetic eukaryote cells. One of the questions that this raises is whether the cycle of size decline and size restoration used by most diatoms to time their life cycle can operate in such small cells. In samples collected from the western Mediterranean during 2009, M. comicus cells were found with diameters ranging from 1.9 to 6.0 μm. The larger cells were initial cells after size restoration, and these still had the valves of their parent cells attached, making it possible to determine the diameter of the threshold below which size restoration could be induced (3.1 μm). During size decline, M. comicus cell shape changed from discoid to spherical. This adaptation helped to reduce and even halt the rate of cell volume decrease, allowing cells to continue to use diameter decline as a clocking mechanism. The results show how adaptable the diatom cell wall can be, in spite of its rigid appearance.
Paraules clau: Marine diatom, Minidiscus comicus, size change, size limit, size restoration, diatomea marina, cambio de tamaño, tamaño límite, tamaño de restauración
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Farré Foix M.,
PhD thesis. Director/es: V.M. Tuset Andújar, A. Lombarte Carrera. Barcelona. (BibTeX: farrefoix.2016b)
Resum: Veure
One of the essential principles provided by the Darwin’s theory of natural selection is that the evolution of organisms and their phenotypic features should be assessed by analyzing the interaction between the anatomical structures of organisms with the external environmental conditions acting on them (Darwin, 1859; Allen, 1907; Thompson, 1917; Bock and von Wahlert 1965). Basing on this premise, since then the study of morphology of organisms attracted high attention within the scientific community, in order to describe and understanding the evolution, adaptations and behaviors of organisms from their morphological and anatomical differences. From its early times, the study of morphology of organisms was focused in descriptive and comparative anatomical analyses used with taxonomical and phylogenic purposes (Bock, 1990). The first references manifesting the relation between the morphology of th species with their surrounding environment appeared at the beginning of the 20 century, suggesting the existence of direct correlations between the phenotype (morphology) and the physic external factors (Allen, 1907), and that this association was the main driver of the evolution of species. This hypothesis was accepted, maintained and incorporated to studies of many scientific branches. In its studies of comparative anatomy from natural observations in the wild, Böker (1935) defined the term “ecological anatomy”, which linked again the morphological features of organisms with the environmental conditions. Other disciplines, such as systematic and genetics, also began to consider these statements in its competences (Dobzhansky, 1937; Mayr, 1942).
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Bartolome R., E. Górriz, J. Dañobeitia, D. Cordoba, D. Martí, A.L. Cameselle, F. Núñez-Cornú, W.L. Bandy, C.A. Mortera-Gutiérrez, D. Nuñez, A. Castellón, J.L. Alonso
Pure and Applied Geophysics, 173, 10, 3575-3594. DOI: 10.1007/s00024-016-1331-y (BibTeX: bartolome.etal.2016c)
Resum: Veure
During the TSUJAL marine geophysical survey, conducted in February and March 2014, Spanish, Mexican and British scientists and technicians explored the western margin of Mexico, considered one of the most active seismic zones in America. This work aims to characterize the internal structure of the subduction zone of the Rivera plate beneath the North American plate in the offshore part of the Jalisco Block, to link the geodynamic and the recent tectonic deformation occurring there with the possible generation of tsunamis and earthquakes. For this purpose, it has been carried out acquisition, processing and geological interpretation of a multichannel seismic reflection profile running perpendicular to the margin. Crustal images show an oceanic domain, dominated by subduction–accretion along the lower slope of the margin with a subparallel sediment thickness of up to 1.6 s two-way travel time (approx. 2 km) in the Middle American Trench. Further, from these data the region appears to be prone to giant earthquake production. The top of the oceanic crust (intraplate reflector) is very well imaged. It is almost continuous along the profile with a gentle dip (<10°); however, it is disrupted by normal faulting resulting from the bending of the plate during subduction. The continental crust presents a well-developed accretionary prism consisting of highly deformed sediments with prominent slumping towards the trench that may be the result of past tsunamis. Also, a bottom simulating reflector (BSR) is identified in the first half a second (twtt) of the section. High amplitude reflections at around 7–8 s twtt clearly image a discontinuous Moho, defining a very gentle dipping subduction plane.
Paraules clau: Jalisco Block, Mexico, Rivera plate, crustal structure, seismic imaging, subduction, earthquake, tsunami, BSR, gas hydrate, trench infill
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Piles Guillem M.,
PhD thesis. Director/es: A. Camps, M. Vall-llossera. (BibTeX: pilesguillem.2016a)
Resum: Veure
Soil moisture is a key state variable of the Earth’s system; it is the main variable that links the Earth’s water, energy and carbon cycles. Soil moisture variations affect the evolution of weather and climate over continental regions, and accurate observations of the Earth’s changing soil moisture are needed to achieve sustainable land and water management, and to enhance weather and climate forecasting skill, flood prediction and drought monitoring. This Ph.D. Thesis focuses on measuring the Earth’s surface soil moisture from space at a global and regional scale. [...]
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Pablos M., J. Martínez-Fernández, M. Piles, N. Sánchez, M. Vall-llossera, A. Camps
Remote Sensing, 8, 587. DOI: 10.3390/rs8070587 (BibTeX: pablos.etal.2016a)
Resum: Veure
Soil moisture (SM) is an important component of the Earth’s surface water balance and by extension the energy balance, regulating the land surface temperature (LST) and evapotranspiration (ET). Nowadays, there are two missions dedicated to monitoring the Earth’s surface SM using L-band radiometers: ESA’s Soil Moisture and Ocean Salinity (SMOS) and NASA’s Soil Moisture Active Passive (SMAP). LST is remotely sensed using thermal infrared (TIR) sensors on-board satellites, such as NASA’s Terra/Aqua MODIS or ESA & EUMETSAT’s MSG SEVIRI. This study provides an assessment of SM and LST dynamics at daily and seasonal scales, using 4 years (2011–2014) of in situ and satellite observations over the central part of the river Duero basin in Spain. Specifically, the agreement of instantaneous SM with a variety of LST-derived parameters is analyzed to better understand the fundamental link of the SM–LST relationship through ET and thermal inertia. Ground-based SM and LST measurements from the REMEDHUS network are compared to SMOS SM and MODIS LST spaceborne observations. ET is obtained from the HidroMORE regional hydrological model. At the daily scale, a strong anticorrelation is observed between in situ SM and maximum LST (R between -0.6 to -0.8), and between SMOS SM and MODIS LST Terra/Aqua day (R close to- 0.7). At the seasonal scale, results show a stronger anticorrelation in autumn, spring and summer (in situ R between -0.5 to -0.7; satellite R between -0.4 to -0.7) indicating SM–LST coupling, than in winter (in situ R close to +0.3; satellite R close to -0.3) indicating SM–LST decoupling. These different behaviors evidence changes from water-limited to energy-limited moisture flux across seasons, which are confirmed by the observed ET evolution. In water-limited periods, SM is extracted from the soil through ET until critical SM is reached. A method to estimate the soil critical SM is proposed. For REMEDHUS, the critical SM is estimated to be close to 0.12m3/m3, stable over the study period and consistent between in situ and satellite observations. A better understanding of the SM–LST link could not only help improving the representation of LST in current hydrological and climate prediction models, but also refining SM retrieval or microwave-optical disaggregation algorithms, related to ET and vegetation status.
Paraules clau: evapotranspiration; correlation; water-limited; energy-limited; coupling; disaggregation; critical soil moisture; REMEDHUS; SMOS; MODIS
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Tilves U., J.E. Purcell, V.L. Fuentes, A. Torrents, M. Pascual, V. Raya, J.-M. Gili, A. Sabatés
Journal of Plankton Research, 38, 5, 1243-1254. DOI: 10.1093/plankt/fbw059 (BibTeX: tilves.etal.2016a)
Resum: Veure
Jellyfish are important predators of fish eggs and larvae and predation is believed to be the main factor determining fish recruitment. The diet of different life stages of Pelagia noctiluca and their potential predation impact on ichthyoplankton were investigated in the NW Mediterranean Sea. In June, the spatial distribution of jellyfish and fish larvae, particularly those of anchovy, overlapped in the study area. Gut content analyses showed relatively high abundance of ichthyoplankton in large medusae, while siphonophores were the most numerous prey of ephyrae. Gut contents, digestion times (DT), and prey and predator abundances were used to estimate predation effects (% of standing stock consumed time−1) of P. noctiluca. Medusae consumed 0.1–0.9% h−1 of the anchovy larvae, while ephyrae consumed 1.5–2.7% h−1 of all fish larvae and 1.5–10.4% h−1 of anchovy larvae. We estimate that medusae and ephyrae consumed 0.02–3.2% h−1 and 0.4–7.1% h−1 of fish eggs, respectively. P. noctiluca can reach extremely high numbers and in a bloom situation it can be an important predator of fish larvae, in particular anchovy. Hence it may play an important role in the planktonic food web with a possible impact on anchovy populations.
Paraules clau: Jellyfish, ichthyoplankton, diet, predation, competition
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Martinez A., C. Domínguez-Carrió, J.M. Gili
Deep-Sea Research. Part I: Oceanographic Research Papers, 112, 57-67. DOI: 10.1016/j.dsr.2016.03.007 (BibTeX: martinez.etal.2016)
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Marti-Puig P., J. Danés, A. Manjabacas, A. Lombarte
Marine and Freshwater Research, 67, 7, 1059-1071. DOI: 10.1071/MF15069 (BibTeX: martipuig.etal.2016a)
Resum: Veure
The three-dimensional (3-D) otolith shapes recently included in the Anàlisi de FORmes d’Otòlits (AFORO) database are defined by means of clouds of points across their surfaces. Automatic retrieval and classification of natural objects from 3-D databases becomes a difficult and time-consuming task when the number of elements in the database becomes large. In order to simplify that task we propose a new method for compacting data from 3-D shapes. The new method has two main steps. The first is a subsampling process, the result of which can always be interpreted as a closed curve in the 3-D space by considering the retained points in an appropriate order. The subsampling preserves morphological information, but greatly reduces the number of points required to represent the shape. The second step treats the coordinates of the 3-D closed curves as periodic functions. Therefore, Fourier expansions can be applied to each coordinate, producing more information compression into a reduced set of points. The method can reach very high information compression factors. It also allows reconstruction of the 3-D points resulting from the subsampling process in the first step. This parameterisation method is able to capture 3-D information relevant to classification of fish species from their otoliths, providing a greater percentage of correctly classified specimens compared with the previous two-dimensional analysis.
Paraules clau: fast Fourier transforms, feature extraction, shape analysis, three-dimensional contour descriptors, three-dimensional shape parameterisation
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Olmedo E., A. Turiel, J. Ballabrera-Poy, J. Martínez, M. Portabella, V. González-Gambau, C. Gabarró, F. Pérez, N. Hoareau, M. Piles, J. Font
Proceedings International Geoscience and Remote Sensing Symposium (IGARSS), Beijing, China, 11-15 July, 2016., . (BibTeX: olmedo.etal.2016c)
Resum: Veure
New ocean products from the Soil Moisture and Ocean Salinity (SMOS) mission are being developed at the Barcelona Expert Centre. Besides the already operational 9- day and monthly sea surface salinity (SSS) products, two additional daily SSS products have been recently become operational: a simple user-friendly product containing all swath-based Level 2 data for each day, and a more elaborated product that uses multifractal fusion techniques to increase the spatial and temporal resolution. Finally, experimental BEC products are also presented which provide SSS values in regions strongly affected by radiofrequency interference (RFI). Recent progress on Land-Sea contamination mitigation has been applied to the BEC products.
Paraules clau: Radiometry, SMOS, salinity
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González-Gambau V., A. Turiel, E. Olmedo, J. Martínez, I. Corbella, A. Camps
IEEE Transactions on Geoscience and Remote Sensing, 54, 4, 2314-2328. DOI: 10.1109/TGRS.2015.2499324 (BibTeX: gonzalezgambau.etal.2016a)
Resum: Veure
Soil moisture and ocean salinity (SMOS) brightness temperature (TB) images and calibrated visibilities are related by the so-called G-matrix. Due to the incomplete sampling at some spatial frequencies, sharp transitions in the TB scenes generate a Gibbs-like contamination ringing and spread sidelobes. In the current SMOS image reconstruction strategy, a Blackman window is applied to the Fourier components of the TBs to diminish the amplitude of artifacts such as ripples, as well as other Gibbs-like effects. In this paper, a novel image reconstruction algorithm focused on the reduction of Gibbs-like contamination in TB images is proposed. It is based on sampling the TB images at the nodal points, that is, at those points at which the oscillating interference causes the minimum distortion to the geophysical signal.Results show a significant reduction of ripples and sidelobes in strongly radio-frequency interference contaminated images. This technique has been thoroughly validated using snapshots over the ocean, by comparing TBs reconstructed in the standard way or using the nodal sampling (NS) with modeled TBs. Tests have revealed that the standard deviation of the difference between the measurement and the model is reduced around 1 K over clean and stable zones when using NS technique with respect to the SMOS image reconstruction baseline. The reduction is approximately 0.7 K when considering the global ocean. This represents a crucial improvement in TB quality, which will translate in an enhancement of the retrieved geophysical parameters, particularly the sea surface salinity
Paraules clau: Image reconstruction, interferometric radiometer, nodal points, nodal sampling (NS), radio-frequency interferences (RFIs), sidelobes, soil moisture and ocean salinity (SMOS).
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Calbet A., C. Schmoker, F. Russo, A. Trottet, M.-S. Mahjoub, O. Larsen, H.Y. Tong, G. Drillet
Science of The Total Environment, 560-561, 284-294. DOI: 10.1016/j.scitotenv.2016.03.234 (BibTeX: calbet.etal.2016)
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Viladrich N., S. Rossi, A. Lopez-Sanz, C. Orejas
Marine Ecology-An Evolutionary Perspective, 37, 1, 46-63. DOI: 10.1111/maec.12247 (BibTeX: viladrich.etal.2016a)
Resum: Veure
Knowledge of the nutritional conditions of coastal commercial fish populations is key to understanding stock health status, and is essential when making reasonable exploitation and management plans. Here, we present the first results on the condition and feeding preferences of two coastal fish species, Diplodus sargus (Linnaeus, 1758) and Pagellus erythrinus (Linnaeus, 1758). Using stable isotope and biochemical analyses, we tested the potential effects of a marine protected area (MPA) and the occurrence of a dramatic coastal storm on the condition and quality of nutrition. The results suggest that both condition (lipids) and nutrition quality (fatty acids, FAs) in P. erythrinus and D. sargus depend upon on food availability in the area in which they were captured. Pagellus erythrinus individuals inside the MPA stored higher quantities of lipids [46.73 ± 19.00 μg lipid·mg organic matter (OM)−1] than those outside the MPA (15.63 ± 5.30 μg lipid·mg OM−1) only before the storm. Diplodus sargus showed different FA signatures inside and outside the MPA before and after the storm. These results suggest that D. sargus increased their quality of nutrition inside (16.62 ± 3.17 μg FA·mg OM−1) versus outside (7.88 ± 2.36 μg FA·mg OM−1) the MPA, owing to increased food diversity and availability. Conversely, P. erythrinus did not show differences in nutritional quality inside (18.12 ± 1.13 μg FA·mg OM−1) or outside (18.81 ± 1.42 μg FA·mg OM−1) the MPA, possibly because of the increase in ingestion not affecting the studied parameters. In P. erythrinus, the FA concentration decreased after the storm, but in D. sargus, a change in lipid composition was observed. These results suggest that P. erythrinus appears to be more impacted by food quality (different saturated and unsaturated FAs) than D. sargus, owing to a more restrictive diet. We hypothesize that the observed differences between inside and outside the MPA are not only related to the degree of protection, but also to the feeding preferences and behaviour of both fishes.
Paraules clau: Fatty acids, fish condition, marine protected areas, stable isotopes, stochastic phenomenon, storm
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Pelegrí J.L.,
Scientia Marina, 80, 4, 567-568. DOI: 10.3989/scimar.04570.20A (BibTeX: pelegri.2016a)
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Colmenero A.I., M. Demestre, P. Sánchez
Cahiers de Biologie Marine, 57, 2, 161-165. (BibTeX: colmenero.etal.2016a)
Resum: Veure
The first specimen of a blind Lophius budegassa found in the Mediterranean Sea was caught during the scientific survey \"COMSOM\" conducted in June 2009 in the fishing grounds off Cap de Creus (NW Mediterranean Sea) with an experimental beam trawl at 90 m depth. The individual is described, and biometric measurements and meristic data provided. The presence of the microsporidian parasite Spraguea lophii was also observed.
Paraules clau: blindness; morphological abnormalities; teratologies; anglerfish; nw mediterranean sea; spraguea
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Lin W., M. Portabella, A. Stoffelen, J. Vogelzang, A. Verhoef
Quarterly Journal of the Royal Meteorological Society, 142, 697, 1745-1756. DOI: 10.1002/qj.2770 (BibTeX: lin.etal.2016m)
Resum: Veure
The two-dimensional variational ambiguity removal (2DVAR) method provides a spatial analysis of the sampled ocean vector winds to resolve the local Advanced Scatterometer (ASCAT) dual wind vector ambiguity. Like other variational meteorological data assimilation systems in numerical weather prediction (NWP), 2DVAR combines ASCAT observations with prior NWP background information, in this case from the European Centre for Medium-range Weather Forecasts (ECMWF). Although 2DVAR is generally effective, it may select the wrong ambiguity under certain conditions, e.g. when the background mislocates frontal areas or low-pressure centres, or when it misses convective systems. The relative influence of the ASCAT and ECMWF wind fields in the resulting 2DVAR analysis field can be controlled by adjusting the background error spatial correlation structure, and the background and/or observation error variances. In this article an adaptive 2DVAR approach is proposed to improve ASCAT ambiguity removal, using background error spatial correlations estimated from the autocorrelation of observed scatterometer wind components minus ECMWF forecasts, and using observation and background errors estimated from triple collocation analysis on collocated buoy, ASCAT and ECMWF data. The triple collocations are segregated into several categories according to the ASCAT-derived parameters that have proven to be effective in detecting the correct position of frontal lines and low-pressure centres. Verification using a typical cyclone case and collocated ASCAT and buoy winds shows that the 2DVAR analysis as well as the ASCAT ambiguity removal is improved significantly by putting more weight on the ASCAT observations using empirically determined spatial background error structure functions and situation-dependent observation/background error variances.
Paraules clau: scatterometer;data assimilation;ambiguity removal;mesoscale;singularity analysis
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Lin W., G. Chiara, M. Portabella, A. Stoffelen, J. Vogelzang, A. Verhoef
Proceedings International Geoscience and Remote Sensing Symposium (IGARSS), Beijing, China, 11-15 July, 2016., . (BibTeX: lin.etal.2016k)
Resum: Veure
In contrast with scatterometer wind data, Numerical Weather Prediction (NWP) models do not well resolve the mesoscale sea surface wind flow under increased wind variability conditions, such as in the vicinity of low-pressure centers, frontal lines, and moist convection. In this paper, several important issues are addressed in order to improve the impact of scatterometer data assimilation into global and regional NWP models, including model error structure functions, situation-dependent Observation/ Background error estimation, and improved scatterometer wind quality control.
Paraules clau: Scatterometer, data assimilation, ambiguity removal, quality control, singularity analysis
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Turiel A., V. González-Gambau, E. Olmedo, J. Martínez, J. Ballabrera-Poy, M. Portabella
Proceedings International Geoscience and Remote Sensing Symposium (IGARSS), Beijing, China, 11-15 July, 2016., . (BibTeX: turiel.etal.2016g)
Resum: Veure
This work is devoted to describe the new processing techniques that are being conceived, developed and implemented at the Barcelona Expert Centre (BEC) for the generation of sea surface salinity (SSS) maps from the Soil Mooisture and Ocean Salinity (SMOS) mission. Several algorithms to mitigate the ripples and sidelobes present in the SMOS brightness temperature (TB) images, to characterize the spatial correlations in the SMOS antennas, to correct for the systematic SSS-derived biases, and to improve the spatial and temporal resolution of the SSS products, have been recently developed and are presented in this paper.
Paraules clau: Nodal sampling, fusion, bias correction
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Lin W., M. Portabella, A. Stoffelen, A. Verhoef, S. Lang, Y. Zhang, M. Lin
Proceedings International Geoscience and Remote Sensing Symposium (IGARSS), Beijing, China, 11-15 July, 2016., . (BibTeX: lin.etal.2016j)
Resum: Veure
This paper reviews several wind quality-sensitive parameters derived from HY-2A scatterometer data, such as the windinversion residual (or Maximum Likelihood Estimator, MLE) and its spatially averaged value, and the singularity exponent (SE) derived from an image processing technique, called singularity analysis. Their sensitivity to data quality is evaluated using the collocated European Centre for Medium-range Weather Forecasting (ECMWF) model output and satellite radiometer rain data. It shows that SE is the best quality indicator, followed by the spatially averaged MLE and the conventional MLE. A set of MLE and SE thresholds are derived from the sensitivity analysis in order to optimize the quality control (QC) for the HY-2A scatterometer.
Paraules clau: HY-2A scatterometer, wind, quality control, singularity exponent, rain
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Dall’Osto M., D.C.S. Beddows, E.J. McGillicuddy, J.K. Esser-Gietl, R.M. Harrison, J.C. Wenger
Atmospheric Chemistry and Physics, 16, 9693-9710. DOI: 10.5194/acp-16-9693-2016 (BibTeX: dallosto.etal.2016a)
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Lin W., M. Portabella, A. Stoffelen, J. Vogelzang, G. De Chiara
(BibTeX: lin.etal.2016n)
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Isla E.,
Polar Biology, 39, 5, 819-828. DOI: 10.1007/s00300-015-1833-6 (BibTeX: isla.2016a)
Resum: Veure
To assess whether sea floor sediment reflects the characteristics of the upper water column, organic carbon (OC) and biogenic silica (bSi) were measured in seventeen 5-cm-long sediment cores recovered within a climatic gradient from the northwestern Weddell Sea (WS) to the Drake Passage (DP) across the Bransfield Strait (BS). Climate settings in the study area vary from dry and cold (polar) conditions with seasonal sea ice coverage in the WS to a more humid and warm (oceanic) environment where no seasonal sea ice develops in the DP, with the BS as transitional zone undergoing seasonal sea ice coverage. OC varied between 0.2 and 1.7 % and represented more than 90 % of the total carbon, and bSi varied between 2 and 13 %. The profiles of both variables along the sediment cores suggested that the surface mixed layer is at least 5 cm thick. The inventories of the upper 5 cm of the sediment column were calculated for both variables. Regional averages were significantly lower for OC in DP samples and higher for bSi in the BS. These results suggested relatively high bSi export to the seabed in the BS, higher degradation for OC in the DP and lower bSi export from the euphotic zone in the WS. The observations made evident that the biogenic matter contents in the sediment not necessarily replicate their production characteristics at the upper ocean even across strong climatic gradients. The results may provide a useful baseline for paleo-reconstructions in a rapidly changing environment.
Paraules clau: Antarctic Peninsula, pelagic–benthic, coupling, biogenic silica, organic carbon, sediment
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Tuset V.M., J.L. Otero-Ferrer, J. Gómez-Zurita, L.A. Venerus, C. Stransky, R. Imondi, A.M. Orlov, Z. Ye, L. Santschi, P.K. Afanasiev, L. Zhuang, M. Farré, M.S. Love, A. Lombarte
Journal of Evolutionary Biology, 29, 10, 2083-2097. DOI: 10.1111/jeb.12932 (BibTeX: tuset.etal.2016b)
Resum: Veure
The sensory drive hypothesis proposes that environmental factors affect both signalling dynamics and the evolution of signals and receivers. Sound detection and equilibrium in marine fishes are senses dependent on the sagittae otoliths, whose morphological variability appears intrinsically linked to the environment. The aim of this study was to understand if and which environmental factors could be conditioning the evolution of this sensory structure, therefore lending support to the sensory drive hypothesis. Thus, we analysed the otolith shape of 42 rockfish species (Sebastes spp.) to test the potential associations with the phylogeny, biological (age), ecological (feeding habit and depth distribution) and biogeographical factors. The results showed strong differences in the otolith shapes of some species, noticeably influenced by ecological and biogeographical factors. Moreover, otolith shape was clearly conditioned by phylogeny, but with a strong environmental effect, cautioning about the use of this structure for the systematics of rockfishes or other marine fishes. However, our most relevant finding is that the data supported the sensory drive hypothesis as a force promoting the radiation of the genus Sebastes. This hypothesis holds that adaptive divergence in communication has significant influence relative to other life history traits. It has already been established in Sebastes for visual characters and organs; our results showed that it applies to otolith transformations as well (despite the clear influence of feeding and depth), expanding the scope of the hypothesis to other sensory structures.
Paraules clau: Adaptation, ecology, otolith shape, phylogeny, rockfishes, sensory drive hypothesis
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Arrieta J.M., C.M. Duarte, M.M. Sala, J. Dachs
Frontiers in Microbiology, 6, 1566, DOI: 10.3389/fmicb.2015.01566 (BibTeX: arrieta.etal.2016a)
Resum: Veure
Volatile and semi-volatile gas-phase organic carbon (GOC) is a largely neglected component of the global carbon cycle, with poorly resolved pools and fluxes of natural and anthropogenic GOC in the biosphere. Substantial amounts of atmospheric GOC are exchanged with the surface ocean, and subsequent utilization of specific GOC compounds by surface ocean microbial communities has been demonstrated. Yet, the final fate of the bulk of the atmospheric GOC entering the surface ocean is unknown. Our data show experimental evidence of efficient use of atmospheric GOC by marine prokaryotes at different locations in the NE Subtropical Atlantic, the Arctic Ocean and the Mediterranean Sea. We estimate that between 2 and 27% of the prokaryotic carbon demand was supported by GOC with a major fraction of GOC inputs being consumed within the mixed layer. The role of the atmosphere as a key vector of organic carbon subsidizing marine microbial metabolism is a novel link yet to be incorporated into the microbial ecology of the surface ocean as well as into the global carbon budget.
Paraules clau: Air-sea exchange, gas-phase organics, GOC, microbial carbon demand, ocean
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Solé J., E. García-Ladona, J. Piera, M. Estrada
Scientia Marina, 80S1, 129-137. DOI: 10.3989/scimar.04271.18A (BibTeX: sole.etal.2016k)
Resum: Veure
Phytoplankton blooms are events of production and accumulation of phytoplankton biomass that influence ecosystem dynamics and may also have effects on socio-economic activities. Among the biological factors that affect bloom dynamics, prey selection by zooplankton may play an important role. Here we consider the initial state of development of an algal bloom and analyse how a reduced grazing pressure can allow an algal species with a lower intrinsic growth rate than a competitor to become dominant. We use a simple model with two microalgal species and one zooplankton grazer to derive general relationships between phytoplankton growth and zooplankton grazing. These relationships are applied to two common grazing response functions in order to deduce the mathematical constraints that the parameters of these functions must obey to allow the dominance of the lower growth rate competitor. To assess the usefulness of the deduced relationships in a more general framework, the results are applied in the context of a multispecies ecosystem model (ERSEM).
Paraules clau: algal blooms; plankton; prey selection; grazing functions; multispecies model; mathematical constraints.
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Abaad M., V.M. Tuset , D. Montero, A. Lombarte, J.L. Otero-Ferrer, R. Haroun
Hydrobiologia, 765, 1, 343-358. DOI: 10.1007/s10750-015-2428-5 (BibTeX: .etal.2016a)
Resum: Veure
Two opportunistic fish species associated with fish farms, bogue (Boops boops) and salema (Sarpa salpa), were studied to infer whether changes in their feeding habits may cause a phenotypic response in body and otolith shape. Specimens were collected close to aquaculture cage sites, called ‘wild-farmed fish’, and from control sites far away from these areas, called ‘wild fish’. The fish body shapes were examined with geometric morphometric analysis using 21 landmarks. The otolith contours were analysed using wavelet function, whereas otolith weights were used as indicators of fish growth rates. Statistically significant differences were observed in body shape between wild-farmed fish and wild fish of both species. The wild-farmed fish had a smaller head and eye, and in bogue also a slighter snout curvature and head depth. Otolith shape and weight did not differ between groups in bogue. By contrast, there were significant differences in otolith shape and weight between groups in salema. A complementary study in salema indicated that the wild-farmed fishes grew more in weight and accumulated higher concentrations of ‘terrestrial fatty acids’ (linoleic and alpha-linolenic acids), which are used in fish feeds. Our findings clearly demonstrated an influence of coastal sea cages on metabolism of some wild fishes.
Paraules clau: Fishes, Morphology, Body, Otolit,h Feeding, Anthropic activity
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Estrada M., M. Delgado, D. Blasco, M. Latasa, A.M.Cabello, V. Benítez-Barrios, E. Fraile-Nuez, P. Mozetič, M. Vidal
Plos One. Open acces, 11, 3, DOI: 10.1371/journal.pone.0151699 (BibTeX: estrada.etal.2016a)
Resum: Veure
We examine the large-scale distribution patterns of the nano- and microphytoplankton collected from 145 oceanic stations, at 3 m depth, the 20% light level and the depth of the subsurface chlorophyll maximum, during the Malaspina-2010 Expedition (December 2010-July 2011), which covered 15 biogeographical provinces across the Atlantic, Indian and Pacific oceans, between 35°N and 40°S. In general, the water column was stratified, the surface layers were nutrient-poor and the nano- and microplankton (hereafter phytoplankton, for simplicity, although it included also heterotrophic protists) community was dominated by dinoflagellates, other flagellates and coccolithophores, while the contribution of diatoms was only important in zones with shallow nutriclines such as the equatorial upwelling regions. We applied a principal component analysis to the correlation matrix among the abundances (after logarithmic transform) of the 76 most frequent taxa to synthesize the information contained in the phytoplankton data set. The main trends of variability identified consisted of: 1) A contrast between the community composition of the upper and the lower parts of the euphotic zone, expressed respectively by positive or negative scores of the first principal component, which was positively correlated with taxa such as the dinoflagellates Oxytoxum minutum and Scrippsiella spp., and the coccolithophores Discosphaera tubifera and Syracosphaera pulchra (HOL and HET), and negatively correlated with taxa like Ophiaster hydroideus (coccolithophore) and several diatoms, 2) a general abundance gradient between phytoplankton-rich regions with high abundances of dinoflagellate, coccolithophore and ciliate taxa, and phytoplankton-poor regions (second principal component), 3) differences in dominant phytoplankton and ciliate taxa among the Atlantic, the Indian and the Pacific oceans (third principal component) and 4) the occurrence of a diatom-dominated assemblage (the fourth principal component assemblage), including several pennate taxa, Planktoniella sol, Hemiaulus hauckii and Pseudo-nitzschia spp., in the divergence regions. Our findings indicate that consistent assemblages of co-occurring phytoplankton taxa can be identified and that their distribution is best explained by a combination in different degrees of both environmental and historical influences.
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Smith L., S.M. Vallina, A. Merico
Scientific Reports, 6, 34170, 1-11. DOI: 10.1038/srep34170 (BibTeX: smith.etal.2016)
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Cuadrat R.R., I. Ferrera, H.P. Grossart, A.M. Dávila
OMICS: A Journal of Integrative Biology, 20, 76-87. DOI: 10.1089/omi.2015.0142 (BibTeX: cuadrat.etal.2016)
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Khomich M., H. Kauserud, R. Logares, S. Rasconi, T. Andersen
FEMS Microbiology, Ecology, 93, 4, 1-13. DOI: 10.1093/femsec/fiw231 (BibTeX: khomich.etal.2016)
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Guidi L., S. Chaffron, L. Bittner, D. Eveillard, A. Larhlimi, S. Roux, Y. Darzi, S. Audic, L. Berline, J.R. Brum, L.P. Coelho, J.C. Espinoza, S. Malviya, S. Sunagawa, C. Dimier, S. Kandels-Lewis, M. Picheral, J. Poulain, S. Searson, L. Stemmann, F. Not, P. Hingamp, S. Speich, M. Follows, L. Karp-Boss, E. Boss, H. Ogata, S. Pesant, J. Weissenbach, P. Wincker, S.G. Acinas, P. Bork, C. de Vargas, D. Iudicone, M.B. Sullivan, J. Raes, E. Karsenti, C. Bowler, G. Gorsky
Nature, 532, 7600, 465-470. DOI: 10.1038/nature16942 (BibTeX: guidi.etal.2016a)
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Ament-Velásquez S.L., E. Figuet, M. Ballenghien, E.E. Zattara, J.L. Norenburg, F.A. Fernández-Álvarez, J. Bierne, N. Bierne, N. Galtier
Molecular ecology, 25, 14, 3356-3369. DOI: 10.1111/mec.13717 (BibTeX: amentvelasquez.etal.2016b)
Resum: Veure
Comparative population genetics in asexual vs. sexual species offers the opportunity to investigate the impact of asexuality on genome evolution. Here we analyse coding sequence polymorphism and divergence patterns in the fascinating Lineus ribbon worms, a group of marine, carnivorous nemerteans with unusual regeneration abilities, and in which asexual reproduction by fissiparity is documented. The population genomics of the fissiparous L. pseudolacteus is characterized by an extremely high level of heterozygosity and unexpectedly elevated πN/πS ratio, in apparent agreement with theoretical expectations under clonal evolution. Analysis of among-species allele sharing and read count distribution, however, reveals that L. pseudolacteus is a triploid hybrid between Atlantic populations of L. sanguineus and L. lacteus. We model and quantify the relative impact of hybridity, polyploidy and asexuality on molecular variation patterns in L. pseudolacteus and conclude that (i) the peculiarities of L. pseudolacteus population genomics result in the first place from hybridization and (ii) the accumulation of new mutations through Meselson's effect is more than compensated by processes of heterozygosity erosion, such as gene conversion or gene copy loss. This study illustrates the complexity of the evolutionary processes associated with asexuality and identifies L. pseudolacteus as a promising model to study the first steps of polyploid genome evolution in an asexual context.
Paraules clau: Clonality, polyploidy, hybridization, population genomics, coding sequences
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1.2 Mb
Chaparro D., M. Vall-llossera, M. Piles, A. Camps, C. Rüdiger, R. Riera-Tatché
IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, 9, 6, 2818--2829. DOI: 10.1109/JSTARS.2016.2571838 (BibTeX: chaparro.etal.2016b)
Resum: Veure
Recent climate trends evidence a rise of temperatures and an increase in the duration and intensity of droughts which is in turn leading to the occurrence of larger wildfires, which threaten the environment as well as human lives and beings. In this context, improved wildfires prediction tools are urgently needed. In this paper, the use of remotely sensed soil moisture data as a key variable in the climate-wildfires relationship is explored. The study is centered in the fires registered in the Iberian Peninsula during the period 2010–2014. Their prior-to-occurrence surface moisturetemperature conditions were analyzed using SMOS-derived soil moisture data and ERA-Interim land surface temperature reanalysis. Results showed that moisture and temperature conditions limited the extent of wildfires, and a potential maximum burned area per moisture-temperature paired values was obtained (R2= 0.43). The model relating fire extent with moisture-temperature preconditions was improved by including information on land cover, regions, and the month of the fire outbreak (R2= 0.68). Model predictions had an accuracy of 83.3% with a maximum error of 40.5 ha. Results were majorly coherent with wildfires behavior in the Iberian Peninsula and reflected the duality between Euro-Siberian and Mediterranean regions in terms of expected burned area. The proposed model has a promising potential for the enhancement of fire prevention services.
Paraules clau: Wildfires, remote sensing, soil moisture measurements,land surface temperature, and burned area.
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Crespo B.G., P.J. Wallhead, R. Logares, C. Pedrós-Alió
Plos One. Open acces, 11, 7, 1-16. DOI: 10.1371/journal.pone.0159195 (BibTeX: crespo.etal.2016)
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Tamames J., P.D. Sánchez, P.I. Nikel, C. Pedrós-Alió
Frontiers in Microbiology, 7, 433, 1-12. DOI: 10.3389/fmicb.2016.00433 (BibTeX: tamames.etal.2016)
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Giménez J., A. Manjabacas, V.M. Tuset, A.Lombarte
Journal of Fish Biology, 89, 4, 2195-2202. DOI: 10.1111/jfb.13115 (BibTeX: gimenez.etal.2016a)
Resum: Veure
Regressions between fish length and otolith size are provided for 40 species from the north-eastern Atlantic Ocean and 142 species from the Mediterranean Sea. Regressions were also estimated at genus level. Most of the regressions (c. 84%) explained a high percentage of the deviance (>75%).
Paraules clau: Atlantic Ocean, fish length, Mediterranean Sea, otolith dimension
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Kiørboe T., R.J. Gonçalves, D. Couespel, H.V. Greve, E. Saiz, P. Tiselius
Limnology and Oceanography, 61, 4, 1169-1171. DOI: 10.1002/lno.10293 (BibTeX: kiorboe.etal.2016)
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Bunse C., D. Lundin, C. Karlsson, N. Akram, M. Vila-Costa, J. Palovaara, L. Svensson, K. Holmfeldt, J. González, E. Calvo, C. Pelejero, C. Marrase, M. Dopson, J.M. Gasol, J. Pinhassi
Nature Climate Change, 6, 483-487. DOI: 10.1038/nclimate2914 (BibTeX: bunse.etal.2016)
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Ribes M., E. Calvo, J. Movilla, R. Logares, R. Coma, C. Pelejero,
Environmental Microbiology Reports, 8, 4, 536-544. DOI: 10.1111/1758-2229.12430 (BibTeX: ribes.etal.2016)
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Isern-Fontanet J., E. Olmedo, A. Turiel, E. García-Ladona
Geophysical Research Letters, DOI: 10.1002/2016GL069595 (BibTeX: isernfontanet.etal.2016a)
Resum: Veure
The circulation in the Algerian Basin is characterized by the presence of fresh-core eddies that propagate along the coast or at distances between 100 and 200 km from the coast. Enhancements in the processing of the Soil Moisture and Ocean Salinity (SMOS) data have allowed to produce, for the first time, satellite sea surface salinity (SSS) maps in the Mediterranean Sea that capture the signature of Algerian eddies. SMOS data can be used to track them for long periods of time, especially during winter. SMOS SSS maps are well correlated with in situ measurements although the former has a smaller dynamical range. Despite this limitation, SMOS SSS maps capture the key dynamics of Algerian eddies allowing to retrieve velocities from SSS with the correct sign of vorticity.
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Le Quéré C., E.T. Buitenhuis, R. Moriarty, S. Alvain, O. Aumont, L. Bopp, S. Chollet, C. Enright, D.J. Franklin, R.J. Geider, S.P. Harrison, A.G. Hirst, S. Larsen, L. Legendre, T. Platt, I.C. Prentice, R.B. Rivkin, S. Sailley, S. Sathyendranath, N. Stephens, M. Vogt, S.M. Vallina
Biogeosciences, 13, 4111-4133. DOI: 10.5194/bg-13-4111-2016 (BibTeX: lequere.etal.2016)
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Calbet A., E. Saiz
Journal of Plankton Research, 38, 3, 690-691. DOI: 10.1093/plankt/fbw032 (BibTeX: calbet.saiz.2016)
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Gallisai R.,
PhD thesis. Director/es: F. Peters. (BibTeX: gallisai.2016c)
Resum: Veure
The potential capacity of fertilization of surface oceans by atmospheric deposition is of scientific interest. This is especially true in the oligotrophic Mediterranean Sea. Its surface waters are extremely poor in nutrients necessary for plankton growth. At the same time, it borders with the largest and most active desert area in the world and the atmosphere over the basin is subject to frequent injections of mineral dust particles. Moreover, future scenarios foresee increases in the region's aridity, thus increasing the dust load, as well as changes in ocean stratification that will increase the potential impact of dust deposition on surface waters. Thus, it is important to study the links between deposition and plankton stimulation. [...]
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Pierdomenico M., E. Martorelli, C. Dominguez-Carrió, J.M. Gili, F.L. Chiocci
Journal of Marine Systems, 157, 101-117. DOI: 10.1016/j.jmarsys.2016.01.005 (BibTeX: pierdomenico.etal.2016)
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9.7 Mb
Narciso A., Valente Gallo F., Cachão A., Cros M., Azevedo L., Barcelos e Ramos E.B.
Continental Shelf Research, 117, 43-65. DOI: 10.1016/j.csr.2016.01.019 (BibTeX: narciso.etal.2016)
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Gasol J.M., C. Cardelús, X.A.G. Morán, V. Balagué, I. Forn, C. Marrasé, R. Massana, C. Pedrós-Alió, M.M. Sala, R. Simó, D. Vaqué, M. Estrada
Scientia Marina, 80, S1, 63-77. DOI: 10.3989/scimar.04480.06E (BibTeX: gasol.etal.2016a)
Resum: Veure
We carried out monthly photosynthesis-irradiance (P-E) experiments with the 14C-method for 12 years (2003–2014) to determine the photosynthetic parameters and primary production of surface phytoplankton in the Blanes Bay Microbial Observatory, a coastal sampling station in the NW Mediterranean Sea. Our goal was to obtain seasonal trends and to establish the basis for detecting future changes of primary production in this oligotrophic area. The maximal photosynthetic rate PBmax ranged 30-fold (0.5-15 mg C mg Chl a–1 h–1), averaged 3.7 mg C mg Chl a–1 h–1 (±0.25 SE) and was highest in August and lowest in April and December. We only observed photoinhibition twice. The initial or light-limited slope of the P-E relationship, αB, was low, averaging 0.007 mg C mg Chl a–1 h–1 (μmol photons m–2 s–1)–1 (±0.001 SE, range 0.001-0.045) and showed the lowest values in spring (April-June). The light saturation parameter or saturation irradiance, EK, averaged 711 μmol photons m–2 s–1 (±58.4 SE) and tended to be higher in spring and lower in winter. Phytoplankton assemblages were typically dominated by picoeukaryotes in early winter, diatoms in late autumn and late winter, dinoflagellates in spring and cyanobacteria in summer. Total particulate primary production averaged 1.45 mg C m–3 h–1 (±0.13 SE) with highest values in winter (up to 8.50 mg C m–3 h–1) and lowest values in summer (summer average, 0.30 mg C m–3 h–1), while chlorophyll-specific primary production averaged 2.49 mg C mg Chl a–1 h–1 (±0.19, SE) and peaked in summer (up to 12.0 mg C mg Chl a–1 h–1 in August). 14C-determined phytoplankton growth rates varied between ca. 0.3 d–1 in winter and 0.5 d–1 in summer and were within 60-80% of the maximal rates of growth, based on PBmax. Chlorophyll a was a good predictor of primary production only in the winter and autumn. Seasonality appeared to explain most of the variability in the studied variables, while phytoplankton composition played a minor role. Daily integrated primary production was fairly constant throughout the year: similar to previous oxygen-based estimates in winter but considerably lower than these in summer. The difference between 14C- and oxygen-based estimates of primary production could be explained by community respiration. Annually integrated primary production amounted to a rather modest 48 g C m–2 yr–1 (equivalent to 130 mg C m–2 d–1). Although no interannual patterns were detected, our work soundly establishes the seasonal trends for the coastal NW Mediterranean, therefore setting the basis for future detection of change.
Paraules clau: Coastal time-series station, primary production, seasonality, photosynthetic parameters, PBmax, αB, estacion costera a largo término, producción primaria, estacionalidad, parámetros fotosintéticos
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Juan C., G. Ercilla, F.J. Hernández-Molina, F. Estrada, B. Alonso, D. Casas, M. García, M. Farran, E. Llave, D. Palomino, J.-T. Vázquez, T. Medialdea, C. Gorini, E. D'Acremont, B. El Moumni, A. Ammar
Marine Geology, 378, 292-311. DOI: 10.1016/j.margeo.2016.01.006 (BibTeX: juan.etal.2016c)
Resum: Veure
A seismic analysis of the Pliocene and Quaternary stratigraphy was conducted in the Alboran Sea (westernmost Mediterranean) using more than 1250 profiles consisting of single- and multi-channel seismic records. This allowed for the updating and renaming of the stratigraphic boundaries and the establishment of a new Pliocene and Quaternary seismic stratigraphy for the Alboran Sea, after the relocation of the base of the Quaternary from 1.8 to 2.6 Ma. The boundaries of the stratigraphic division are as follows: the Messinian (M at 5.96 to 5.33 Ma), the intra-lower Pliocene (P0 at ca. 4.5 Ma), the top of the Zanclean (P1 at ca.3.3 Ma), the base of the Quaternary (BQD at ca. 2.6 Ma), the top of the Gelasian (Q0 at ca. 1.8 Ma), the intra-lower Quaternary (Q1 at ca. 1.12 Ma), and the top of the Calabrian (Q2 at ca. 0.7 Ma). Additionally, for the first time, the seismic analysis allowed us to present and discuss the evidence of contourite features reaching the scale of the Alboran Basin. Contourite drifts (plastered, sheeted, elongated separated and confined monticular drifts) and erosive features (terraces, scarps, moats and channels) were developed under the continuous influence of Mediterranean water masses (light and dense), after the opening of the Strait of Gibraltar in the latest Miocene (5.46 Ma). There are at least two primary factors controlling the contourite features, based on the seismic analysis, as follows: i) tectonics, which has governed the relocation of the main Mediterranean flow pathways and their circulation patterns; and ii) climate, which has influenced both water mass conditions (interfaces) and hinterland sediment sources, conditioning the morpho-seismic expression and growth pattern of the drifts and terrace formation (dimensions). The distribution of contourite features through time and space has allowed us to propose the three following main scenarios for ocean circulation since the opening of the Strait of Gibraltar: Atlantic Zanclean flooding; the Pliocene sea, with two different stages for the dense circulation; and the Quaternary sea, with well-defined and stable interfaces for the Atlantic Waters (AW), light and dense Mediterranean waters.
Paraules clau: Contourites, Alboran Sea, Pliocene and Quaternary, stratigraphy, palaeoceanography
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Farré M., V.M. Tuset, F. Maynou, L. Recasens, A. Lombarte
Scientia Marina, 80, 2, 175-186. DOI: 10.3989/scimar.04280.15A (BibTeX: farre.etal.2016c)
Resum: Veure
We applied and compared three different sets of landmarks and semilandmarks commonly used in studies of fish assemblages to identify a standardized method of landmark selection that includes the maximum amount of morphological information of species. The different landmark-based methods used produced differences regarding the distribution of case-study species within the morphospace. We suggest that adding landmarks and semilandmarks that provide more specific information about anatomical structures with important roles in the biology of species, such as transformed fins or sensory organs, contributes to a clearer differentiation of species within the morphospace and a better interpretation of their occupancy. In addition, three types of method were used to establish how species are distributed within morphospace. The results demonstrated that aggregation points methods, including analyses based on quadrants or distances, are more appropriate for this purpose than indices of morphological disparity. The results also confirmed that although numerical methods are needed to test the statistical significance of outcomes, graphical methods provide a more intuitive interpretation of morphospace occupancy. The kernel density and Gabriel graph were useful to infer the morphospace zone where species are more densely grouped, improving the knowledge of space occupancy and structural complexity of fish assemblages. Selección de puntos homólogos (landmarks) y equidistantes (semilandmarks) en peces para análisis de morfometría geométrica: un estudio comparativo basado en métodos analíticos. En el presente estudio se compara la estructura de una comunidad de peces a partir del análisis morfológico de puntos homólogos (landmarks) y equidistantes (semilandmarks) en las especies de dicha comunidad. Para este propósito, se utilizaron tres metodologías distintas descritas en la literatura a la hora de definir dichos puntos con el fin de identificar cuál de ellas incluía la máxima cantidad de información morfológica posible sobre las especies. Las tres opciones proporcionaron diferentes resultados en relación a la distribución de las especies dentro del morfoespacio. Los resultados sugirieron que la incorporación de puntos que proporcionen información más específica sobre estructuras anatómicas que tienen papeles importantes en la biología de las especies, como aletas modificadas u órganos sensoriales, contribuye a una diferenciación más clara de las especies y a una mejor interpretación de la ocupación del morfoespacio. Adicionalmente, varios métodos numéricos y gráficos se emplearon con el fin de establecer cómo las especies se distribuyen dentro del morfoespacio. Los resultados demostraron que los métodos de agregación de puntos, incluyendo análisis basados en cuadrantes o distancias, fueron más apropiados para este propósito que los índices de disparidad morfológica. Además, los resultados también confirmaron que aunque los métodos numéricos fueron necesarios para evaluar la significancia estadística de los mismos, los métodos gráficos proporcionaron una interpretación más intuitiva y clara de la distribución de las especies dentro del morfoespacio. La densidad de Kernel y los gráficos de Gabriel se mostraron muy útiles a la hora de deducir la zona del morfoespacio donde las especies estaban más densamente agrupadas, hecho que ayudó a mejorar el conocimiento de la ocupación del espacio y de la complejidad estructural en comunidades de peces.
Paraules clau: morphological traits, landmarks, geometric morphometrics, diversity, point pattern, morphospace, marine fishes, características morfológicas, puntos homólogos, morfometría geométrica, diversidad, patrón de puntos, morfoespacio, peces marinos
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Teixidó N., N. Bensoussan, A. Gori, I. Fiorillo, N Viladrich
Marine Ecology, 37, 134-144. DOI: 10.1111/maec.12255 (BibTeX: teixido.etal.2016)
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Gemma Ercilla ., C. Juan, F.J. Hernández-Molina, M. Bruno, F. Estrada, B. Alonso, D. Casas, M. Farran, E. Llave, M. García, J.T. Vázquez, E. D\'Acremont, C. Gorini, D. Palomino, J. Valencia, B. El Moumni, A. Ammari
Marine Geology, 378, 157-170. DOI: 10.1016/j.margeo.2015.09.007 (BibTeX: ercilla.etal.2016a)
Resum: Veure
We present an interdisciplinary study of the geomorphology, sedimentology and physical oceanography of the Alboran Sea (south-western Mediterranean Sea) to evaluate the potential role of bottom currents in shaping the Spanish and Moroccan continental margins and adjacent basins. Bathymetric and seismic data have allowed the recognition of the contourite deposits, including depositional (plastered, sheeted, channel-related, mounded confined, elongated and separated drifts), erosive (moats, channels and furrows) and mixed (terraces and scarps) features. Hydrographic data offer new insights into the distribution of the Mediterranean water masses, and reveal that bottom circulation of the Western Intermediate Water (WIW) and the Levantine Intermediate Water (LIW) interact with the Spanish slope, and the Western Mediterranean Deep Water (WMDW) on the Moroccan slope, Spanish base-of-slope and deep basins. The integration of distinct datasets and approaches allows a proposal of a new sedimentary model for the Alboran Sea that details the significance of bottom current processes in shaping deep-sea morphology. This model considers the bottom circulation of water masses governs physiography, that interface positions of water-masses with contrasting densities sculpt terraces on a regional scale, and that the morphologic obstacles play an essential role in the local control of processes and water-mass distributions. Our findings demonstrate the pivotal role of bottom water circulation in seafloor shaping and sedimentary stacking patterns for continental margins, establishing a new outlook for future studies of deep marine sedimentation.
Paraules clau: Geomorphology, contourites, bottom currents, continental margin, water-masses interfaces, Alboran Sea
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Martín-Neira M., R. Oliva, I. Corbella, F. Torres, N. Duffo, I. Durán, J. Kainulainen, J. Closa, A. Zurita, F. Cabot, A. Khazaal, E. Anterrieu, J. Barbosa, G. Lopes, J. Tenerelli, R. Díez-García, J. Fauste, F. Martín-Porqueras, V. González-Gambau, A. Turiel, S. Delwart, R. Crapolicchio, M. Suess
Remote Sensing of Environment, 180, 19-39. DOI: 10.1016/j.rse.2016.02.036 (BibTeX: martinneira.etal.2016b)
Resum: Veure
ESA's Soil Moisture and Ocean Salinity (SMOS) mission, launched 2-Nov-2009, has been in orbit for over 6 years, and its Microwave Imaging Radiometer with Aperture Synthesis (MIRAS) in two dimensions keeps working well. The calibration strategy remains overall as established after the commissioning phase, with a few improvements. The data for this whole period has been reprocessed with a new fully polarimetric version of the Level-1 processor which includes a refined calibration schema for the antenna losses. This reprocessing has allowed the assessment of an improved performance benchmark. An overview of the results and the progress achieved in both calibration and image reconstruction is presented in this contribution.
Paraules clau: Soil Moisture and Ocean Salinity (SMOS)Mission, Soil moisture, Sea surface salinity, L-Band radiometry, Aperture synthesis, MIRAS
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Giakoumi S., F. Guilhaumon, S. Kark, A. Terlizzi, J. Claudet, S. Felline, C. Cerrano, M. Coll, R. Danovaro, S. Fraschetti, D. Koutsoubas, J.B. Ledoux, T. Mazor, B. Mérigot, F. Micheli, S. Katsanevakis
Diversity and Distributions, 22, 12, 1220-1231. DOI: 10.1111/ddi.12491 (BibTeX: giakoumi.etal.2016b)
Resum: Veure
Biological invasions are major contributors to global change and native biodiversity decline. However, they are overlooked in marine conservation plans. Here, we examine for the first time the extent to which marine conservation planning research has addressed (or ignored) biological invasions. Furthermore, we explore the change of spatial priorities in conservation plans when different approaches are used to incorporate the presence and impacts of invasive species. Location Global analysis with a focus on the Mediterranean Sea region. Methods We conducted a systematic literature review consisting of three steps: (1) article selection using a search engine, (2) abstract screening and (3) review of pertinent articles, which were identified in the second step. The information extracted included the scale and geographical location of each case study as well as the approach followed regarding invasive species. We also applied the software Marxan to produce and compare conservation plans for the Mediterranean Sea that either protect, or avoid areas impacted by invasives, or ignore the issue. One case study focused on the protection of critical habitats, and the other on endemic fish species. Results We found that of 119 papers on marine spatial plans in specific biogeographic regions, only three (2.5%) explicitly took into account invasive species. When comparing the different conservation plans for each case study, we found that the majority of selected sites for protection (ca. 80%) changed in the critical habitat case study, while this proportion was lower but substantial (27%) in the endemic fish species case study. Main conclusions Biological invasions are being widely disregarded when planning for conservation in the marine environment across local to global scales. More explicit consideration of biological invasions can significantly alter spatial conservation priorities. Future conservation plans should explicitly account for biological invasions to optimize the selection of marine protected areas.
Paraules clau: Alien species, biological invasions, conservation planning, impacts, management actions, marine biogeographic regions, marine protected areas, Mediterranean Sea
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Martinez J., A. Turiel, V. González-Gambau, E. Olmedo
IEEE Transactions on Geoscience and Remote Sensing, 54, 8, 4906-4910. DOI: 10.1109/TGRS.2016.2552647 (BibTeX: martinez.etal.2016b)
Resum: Veure
Since its launch in 2009, the European Space Agency mission Soil Moisture and Ocean Salinity (SMOS) has provided valuable information on soil moisture, sea surface salinity data, and other geophysical variables. Due to its innovative instrument, an L-band 2-D synthetic aperture interferometric radiometer, SMOS is able to provide high-resolution L2 data (as compared with other L-band missions). However, SMOS processing is complex, giving rise to the emergence of some unexpected biases. In this paper, we have analyzed the spatial structure of two-point correlations owing to the SMOS synthetic antenna, finding that they are not negligible. Those correlations can be characterized by means of effective point spread functions (PSFs). This paper indicates that theSMOS PSFmatrix can be computed in a fast way from measured data without the need for any model or auxiliary data. Furthermore, this matrix can be described in terms of a convolution kernel. The knowledge of that convolution kernel can be used to improve the quality of theSMOS image and to assess the effect of changes of processing procedures, including calibration methods.
Paraules clau: Imaging, point spread functions (PSFs), radiometry, remote sensing, signal processing, Soil Moisture and Ocean Salinity (SMOS).
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Ribó M., P. Puig, R. Urgeles, D. Van Rooij, A. Muñoz
Marine Geology, 378, 276-291. DOI: 10.1016/j.margeo.2015.11.011 (BibTeX: ribo.etal.2016b)
Resum: Veure
Several fields of large-scale sediment waves have been observed along the Gulf of Valencia continental margin (NW Mediterranean). The largest sediment waves develop on the continental slope, extending from 250 to 850 m water depth, with wavelengths ranging between 500 m and 1000 m and wave heights from ~ 2 m to ~ 50 m. On the lower part of the slope, sediment waves are quasi-stationary “vertically accreting”, becoming up-slope migrating towards the mid- and upper part of the slope. A second group of sediment waves have developed over the outer continental shelf, with wavelengths of 400 to 800 m and heights of 2 to 4 m, also displaying an up-slope migrating pattern. Multi-channel seismic lines crossing the continental margin show that the sediment waves over the continental slope region have been continuously developed on the foreset region of the prograding margin clinoform. Several units of sediment waves have been identified in the sedimentary record, evolving in accordance with the margin progradation. Detailed analysis of single-channel (sparker) seismic profiles revealed the presence of several sediment depositional subunits over the outer continental shelf, some of them with successive development of sediment waves being truncated by erosive surfaces, likely related to Quaternary eustatic sea-level oscillations. These erosional surfaces can be followed downslope into paraconformable strata of the sediment waves on the continental slope, where constant bedform growth is observed, without being affected by sea level changes. Based on geophysical data, the thickness of the sediment waves mapped units show that the largest sediment waves (in wave ratio, length and height) develop where sediment deposition rates are the highest, coinciding with the upper part of the continental slope (foreset clinoforms), confined by the presence of structural highs. The development of these sediment waves has been previously explained by the interaction of internal waves over the continental slope. Because sediment waves are preserved in the sedimentary record since the Lower/Pliocene, internal waves activity could have been present in this part of the margin shortly after the Zanclean reflooding of the Mediterranean Basin, following the Messinian desiccation event ~ 5.6 My ago. Deep water hydrodynamic conditions were re-established at that time, modulating sediment transport and deposition over the continental slope and outer continental shelf.
Paraules clau: Sediment waves; Plio-Quaternary sedimentary record; Internal waves; Gulf of Valencia continental margin; NW Mediterranean
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Pascual M.,
PhD thesis. Director/es: V. Fuentes, J.L. Acuña. (BibTeX: pascual.2016a)
Resum: Veure
Salps are marine pelagic tunicates that have opportunistic skills to bloom under favorable conditions and persist during adverse periods. They quan experience population outbursts (blooms) which, combined with their efficient feeding mechanism, produce several ecological and societal consequences. Although salp blooms are common in the Catalan Sea during spring and autumn, their causes and effects on the ecosystem have never been studied in this area before. The general aim of the present thesis is to understand the spatial and temporal processes leading to salp blooms and estimate their trophic impact in the Catalan Sea, northwestern Mediterranean Sea. For this purpose, mechanistic (matrix models) and statistical models (GAMs) combined with in situ observations allowed us to propose the simplest mechanisms to account for bloom development. In contrast to previous hypotheses, we found that changes in female reproduction drive the population to latency under unfavorable conditions and trigger the bloom when conditions improve (Chapter 1). From a spatial scale, hydrodynamic factors mainly drove high local salp abundances, although biological variables (predator abundance) had secondary importance (Chapter 2). We observed the coexistence of contrasting diel vertical migration (DVM) patterns in a salp (nocturnal and diurnal migrations), which explains controversial conclusions in previous studies, but brings new questions about the drivers of DVM in salps (Chapter 3). The two species found produced contrasting trophic impacts: Thalia democratica was less abundant and its effect on the ecosystem seemed to be negligible while, Salpa fusiformis ingested a maximum of 69.92 mg C m-2 day-1 and defecated 35.76 mg C m-2 day-1 , contributing to the transport of organic matter to the deep ocean (Chapter 2). Our findings lead us to consider evolutionary demographic studies to understand the potential benefits of their life cycle for the adaptability to short-time scale environmental changes and the mechanisms which maintain genetic variability after bloom-latency periods.
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Fernández Guallart E.,
PhD thesis. Director/es: F. Pérez, C. Pelejero. (BibTeX: fernandezguallart.2016a)
Resum: Veure
The ocean carbon sink contributes to mitigate global warming. However, the resulting anthropogenic CO2 (C ant) oceanic invasion affects the chemical balances of the CO system in seawater, which translates into a decrease in surface ocean pH. The North Atlantic Ocean presents the largest Cant storage rate of all oceans. The key mechanism contributing to this high value is the northward transport of warm tropical and subtropical waters that contain high Cant concentrations from low latitudes poleward into the regions of deep water formation, through the upper limb of the Atlantic Meridional Overturning Circulation. These deep waters return southward into the Deep Western Boundary Current (DWBC) containing moderate but increasing Cant levels. Given the predominant part of the (sub)tropical North Atlantic region in the uptake of atmospheric Cant , the anthropogenically derived acidification and taking into account the role of ocean circulation on the distribution of the absorbed Cant between basins, this thesis assesses de decadal changes and trends in some parameters of the carbonate system along two oceanographic sections located at 24.5°N and at 7.5°N of latitude, occurred between the early 1990s and the early 2010s. We assessed the interactions between ocean circulation and the carbonate system, in particular regarding the processes that control and modulate the storage rates of Cant and the associated acidification. This was accomplished by splitting the water masses present in each of the two sections into separated zonal regions that were defined following oceanographic criteria. This methodological approach showed that the spatiotemporal variability in the storage of Cant along the two sections is strongly related with the deep Cant signal conveyed by the main circulation current (i.e. DWBC) that spreads across the two sections. The deconvolution of the temporal pH differences into anthropogenic and non-anthropogenic (natural) components revealed that these are of similar magnitudes but have different representations with depth and longitude. Our results emphasize the need to provide more insight into natural variability of the parameters of the carbonate system, with the aim of providing further insight on the predictability of the observed trends for time periods over decadal timescales.
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Llopart J.,
PhD thesis. Director/es: R. Urgeles, A. Camerlenghi. Barcelona. (BibTeX: llopart.2016a)
Resum: Veure
Late Quaternary climate variations controlled glacial advances and retreats to the shelf edge and therefore the evolution of high latitude continental margins. The variations in ice extension modulated sediment supply to the continental slope resulting in a particular shape and stratigraphy but also exerted a major control on stresses imposed on marine sediments and likely had a major control on fluid flow pattern. This thesis investigates the sedimentary, stratigraphic and hydrogeologic evolution of two Arctic Trough Mouth Fans (TMFs), the Storfjorden and Kveithola TMFs in the NW Barents Sea, from ~2.7 Ma to Present, and identifies how such evolution affected slope instability of the TMFs. The research is carried out by means of sub-bottom and seismic reflection profiles, multibeam bathymetry data and sediment cores on which sedimentological and geotechnical analysis have been performed. Numerical finite elements models allow inferring the detailed stratigraphic architecture and hydrogeological evolution of the TMFs. We found that the Storfjorden and Kveithola TMFs mainly consist of an alternation of rapidly deposited glacigenic debris flows during glacial maxima and a sequence of well-layered plumites and hemipelagic sediments, which were mainly deposited during the deglaciation phase of the adjacent glacial trough. We have identified eight units above regional reflector R1, which indicate that the ice sheet reached the shelf edge within the Storfjorden Trough on at least three occasions during the last ~200 ka. A shallow subsurface unit of glacigenic debris flows suggests that the ice sheet had a short re-advance over the northern and central part of Storfjorden after the Last Glacial Maximum. From stratigraphy, core and literature data, we estimate that ice sheets reached the shelf edge between 19.5 to 22.5 ka, 61 to 65 ka and 135 to 167 ka. [...]
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Tomlinson B., F. Maynou, A. Sabatés, V. Fuentes, A. Canepa, S. Sastre
Estuarine, Coastal and Shelf Science, DOI: 10.1016/j.ecss.2015.11.012 (BibTeX: tomlinson.etal.2016)
Resum: Veure
Despite the large fluctuation in annual recordings of gelatinous plankton along the Catalan coast in the north western Mediterranean and the lack of long term data sets, there is a general perception that jellyfish abundances are increasing. Local authorities are concerned about the stranding events and arrivals of jellyfish to beaches and believe it could reduce the recreational appeal of the beaches – a valuable ecosystem service for the regional tourist industry. Previous studies also demonstrate the predation of jellyfish (Pelagia noctiluca ephyrae) upon some small pelagic fish larvae (Engraulis encrasicolus). Small pelagics are the principal source of revenue for the local fisheries. A social-ecological model was created in order to capture the effects of changes in abundance of P. noctiluca upon the local fisheries, the tourist industry and the wider economy. The following sub-models were constructed and connected following the systems approach framework methodology: an age-class based fisheries model; a jellyfish population matrix model; a jellyfish stranding model; a study on the impact of jellyfish strandings on beach users; and an economic input–output matrix. Various future scenarios for different abundances of jellyfish blooms were run. The “Expected blooms” scenario is similar to the quantity and size of blooms for 2000–2010. For a hypothetical “No blooms” scenario (standard background level of jellyfish but without any blooms) landings would increase by around 294 tonnes (5.1%) per year (averaged over 10 years) or approximately 0.19 M€ in profits per year (4.5%), and strandings would decrease by 49%. In a “Frequent blooms” scenario, landings would decrease by around 147 tonnes per year (2.5%) and decrease profits by 0.10 M€ per year (2.3%), and strandings would increase by 32%. Given the changes that these scenarios would cause on the regional gross domestic product and employment, this study concludes that the overall impact of either of these scenarios on the economy would not be significant at the regional scale.
Paraules clau: Pelagia noctiluca, anchovy, sardine, small pelagic fisheries, social-ecosystem model, jellyfish strandings, Mediterranean, Spain, Catalonia
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Segura-Noguera M., D. Blasco, J.M. Fortuño
Plos One. Open acces, 11, 4, e0154050. DOI: 10.1371/journal.pone.0154050 10.1371/journal.pone.0154050 (BibTeX: seguranoguera.etal.2016a)
Resum: Veure
Here we present, for the first time, the elemental concentration, including C, N and O, of single phytoplankton cells collected from the sea. Plankton elemental concentration and stoichiometry are key variables in phytoplankton ecophysiology and ocean biogeochemistry, and are used to link cells and ecosystems. However, most field studies rely on bulk techniques that overestimate carbon and nitrogen because the samples include organic matter other than plankton organisms. Here we used X-ray microanalysis (XRMA), a technique that, unlike bulk analyses, gives simultaneous quotas of C, N, O, Mg, Si, P, and S, in single-cell organisms that can be collected directly from the sea. We analysed the elemental composition of dinoflagellates and diatoms (largely Chaetoceros spp.) collected from different sites of the Catalan coast (NW Mediterranean Sea). As expected, a lower C content is found in our cells compared to historical values of cultured cells. Our results indicate that, except for Si and O in diatoms, the mass of all elements is not a constant fraction of cell volume but rather decreases with increasing cell volume. Also, diatoms are significantly less dense in all the measured elements, except Si, compared to dinoflagellates. The N:P ratio of both groups is higher than the Redfield ratio, as it is the N:P nutrient ratio in deep NW Mediterranean Sea waters (N:P = 20-23). The results suggest that the P requirement is highest for bacterioplankton, followed by dinoflagellates, and lowest for diatoms, giving them a clear ecological advantage in P-limited environments like the Mediterranean Sea. Finally, the P concentration of cells of the same genera but growing under different nutrient conditions was the same, suggesting that the P quota of these cells is at a critical level. Our results indicate that XRMA is an accurate technique to determine single cell elemental quotas and derived conversion factors used to understand and model ocean biogeochemical cycles.
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Pascual M., F. Palero, V.H. García-Merchán, E. Macpherson, A. Robainas-Barcia, F. Mestres, T. Roda, P. Abelló
Scientific Reports, 6, 29892, DOI: 10.1038/srep29892 (BibTeX: pascual.etal.2016a)
Resum: Veure
Spatial genetic studies often require sampling broadly separated areas, difficult to access simultaneously. Although comparing localities surveyed at different time periods might result in spurious genetic differentiation, there is a general believe on the stability of genetic structure through time, particularly if sampled localities are isolated or very distant. By analysing spatial and temporal genetic differentiation of the portunid crab Liocarcinus depurator we assessed the contribution of historical and contemporary processes on population connectivity patterns across three main oceanographic discontinuities along the Atlantic-Mediterranean transition: Gibraltar Strait, Almeria-Oran Front and Ibiza Channel. A partial fragment of the cytochrome oxidase I gene was sequenced in 366 individuals collected from localities at both sides of each discontinuity during three time periods. Although localities showed genetic fluctuations through time, a significant gradient was detected along the coast for all sampling periods. Significant inter-annual differences identified within the Alicante area, north of the Almeria-Oran Front, were associated with shifts in the relative contribution of Atlantic and Mediterranean water masses. The persistence of a clinal pattern in the Atlantic-Mediterranean transition area together with local fluctuations suggests a complex balance of dispersal and selection.
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Grifoll M., A.L. Aretxabaleta, J.L. Pelegrí, M. Espino
Ocean Science, 12, 1, 137-151. DOI: 10.5194/os-12-137-2016 (BibTeX: grifoll.etal.2016a)
Resum: Veure
We investigate the rapidly changing equilibrium between the momentum sources and sinks during the passage of a single two-peak storm over the Catalan inner shelf (NW Mediterranean Sea). Velocity measurements at 24 m water depth are taken as representative of the inner shelf, and the cross-shelf variability is explored with measurements at 50 m water depth. During both wind pulses, the flow accelerated at 24 m until shortly after the wind maxima, when the bottom stress was able to compensate for the wind stress. Concurrently, the sea level also responded, with the pressure-gradient force opposing the wind stress. Before, during and after the second wind pulse, there were velocity fluctuations with both super- and sub-inertial periods likely associated with transient coastal waves. Throughout the storm, the Coriolis force and wave radiation stresses were relatively unimportant in the along-shelf momentum balance. The frictional adjustment timescale was around 10 h, consistent with the e-folding time obtained from bottom drag parameterizations. The momentum evolution at 50 m showed a larger influence of the Coriolis force at the expense of a decreased frictional relevance, typical in the transition from the inner to the mid-shelf.
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Tuset V. M., M. Farré, J.L. Otero-Ferrer, A. Vilar, B. Morales-Nin, A. Lombarte
Marine and Freshwater Research, 67, 7, 1037-1048. DOI: 10.1071/MF15052 (BibTeX: m.tuset.etal.2016a)
Resum: Veure
To check the suitability of otoliths for measuring biodiversity, the contour and shape of the sulcus acusticus of sagittal otoliths were described using geometric morphological analysis. Thirteen and fourteen points were used to define these structures respectively. Three current coastal fish assemblages of the north-western Mediterranean were selected for the present study. The results demonstrate that the relative warps generated in the geometric analysis explained both characteristics related to contour and the otolith sulcus. A comparative study with body fish shape using morphospaces and clusters revealed that otolith shape is a better variable for explaining the ecological structure of a fish assemblage. Moreover, three morphological indices (morphological richness (MR), morphological disparity and the morphogeometric index) were estimated from relative warps of otoliths and were compared with ecological, taxonomic, functional and morphological (from body shape) indices. MR increased with functional diversity and average taxonomic distinctness, reflecting the ecological and taxonomic character of otolith morphology. These findings suggest that otoliths could be a useful tool for studying the diversity of present and past fish assemblages.
Paraules clau: geometric morphology, otolith shape
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Segura-Noguera M., A. Cruzado, D. Blasco
Scientia Marina, 80, S1, 39-56. DOI: 10.3989/scimar.04309.20A (BibTeX: seguranoguera.etal.2016c)
Resum: Veure
Reference depth profiles of dissolved inorganic nutrients, dissolved oxygen and chlorophyll a are described for the Catalan Sea using quality controlled data. Phosphate, nitrate and silicate show typical nutrient profiles, with nutriclines at different depths. Maximums of nitrite, dissolved oxygen and occasionally ammonium are found within the photic zone, close to the deep chlorophyll maximum. In intermediate waters we found a minimum of dissolved oxygen coincident with maximum concentrations of phosphate and nitrate. Ammonium concentration is unexpectedly high in the mesopelagic zone, where there are still measurable nitrite concentrations. The origin of such high ammonium and nitrite concentrations remains unclear. We also identify and describe anomalous data and profiles resulting from eutrophication, western Mediterranean Deep Water formation and dense shelf water cascading. The N:P ratio in deep waters is 22.4, which indicates P limitation relative to the Redfield ratio. However, the N:P ratio above the deep chlorophyll maximum in stratified surface waters is <4 (<8 including ammonium). The depth profiles of key biogeochemical variables described in this study will be a useful reference for future studies in the Catalan Sea (NW Mediterranean Sea) in order to validate data sampled in this area, to identify anomalous processes, and to study the evolution of the ecosystem following the undergoing global change.
Paraules clau: dissolved inorganic nutrients, dissolved oxygen, chlorophyll a, stoichiometry, P limitation, NW MediterraneanSea, Catalan Sea, nutrientes inorgánicos disueltos, oxígeno disuelto, clorofila a, estequiometría, limitación por fósforo, mar Catalán, mar Mediterráneo
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Olivar M.P., J.I. González-Gordillo, J. Salat, G. Chust, A. Cózar, S. Hernández-León, M.L. Fernández de Puelles, X. Irigoien
Marine and Freshwater Research, 67, 8, 1114-1127. DOI: 10.1071/MF14391 (BibTeX: olivar.etal.2016)
Resum: Veure
Surface waters are an attractive foraging ground for small fish in the open ocean. This study aims to determine the importance of vertically migrating species in the neuston of oceanic waters across the Atlantic, Indian and Pacific Oceans and to ascertain the influence of environmental variables on their distribution patterns. Neustonic fish assemblages were primarily controlled by light. They were dominated by late-larvae and juveniles of Exocoetidae, Hemiramphidae and Scomberesocidae during the day. At night, the vertical migration of mesopelagic species changed the dominance pattern in favour of Myctophidae and Scomberesocidae. The neustonic families’ distribution was primarily related to sea surface temperatures, whereas environmental variables at deeper layers were related to mesopelagic migrating families. Canonical correspondence analysis showed a low but statistically significant contribution of several environmental variables to myctophid species composition (10%), with minimum oxygen concentrations ranking first in variance explanation followed by maximum fluorescence, sea surface temperature and 400-m temperature. Spatial autocorrelation also explained 17% of the variance, indicating the influence of other factors such as historical, demographic and dispersal constraints. The low number of myctophid species in the North Pacific Equatorial Countercurrent appears to be related to the low oxygen concentrations observed in this province.
Paraules clau: Ichthyoneuston, ichthyoplankton, micronekton, Myctophidae, oceanic realm, pelagic biogeography, vertical migration
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Solé J., E. Berdalet, L. Arin, Ll. Cros, M. Delgado, A. Kuwata, C. Llebot, C. Marrasé
Scientia Marina, 80, S1, 33-38. DOI: 10.3989/scimar.04520.06D (BibTeX: sole.etal.2016e)
Resum: Veure
Plankton ecology has been the object of intense research and progress in the last few decades. This has been partly due to technological advances that have facilitated the multidisciplinary and high-resolution sampling of ecosystems and improved experimentation and analytical methodologies, and to sophisticated modelling. In addition, exceptional researchers have had the vision to integrate all these innovative tools to form a solid theoretical background in ecology. Here we provide an overview of the outstanding research work conducted by Professor Marta Estrada and her pioneering contribution to different areas of research in the last four decades. Her research in biological oceanography has mainly focussed on phytoplankton ecology, taxonomy and physiology, the functional structure of plankton communities, and physical and biological interactions in marine ecosystems. She has combined a variety of field and laboratory approaches and methodologies, from microscopy to satellite observations, including in-depth statistical data analysis and modelling. She has been a reference for scientists all over the world. Here, her contributions to plankton ecology are summarized by some of her students and closest collaborators, who had the privilege to share their science and everyday experiences with her.
Paraules clau: Phytoplankton ecology, taxonomy, functional structure of plankton communities, physical-biological interactions, ecología del fitoplancton, taxonomía, estructura funcional de las comunidades plantónicas, interacciones física-biología
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Juan Valenzuela C.,
PhD thesis. Director/es: G. Ercilla Zarraga, F.J. Hernández Molina, T. Medialdea Cela, M. Canals Artigas. (BibTeX: juanvalenzuela.2016a)
Resum: Veure
An interdisciplinary study of the geomorphology, sedimentology, stratigraphy and physical oceanography of the deep-sea environments of the Alboran Sea (south western Mediterranean Sea) has been carried out with the purpose of evidencing and understanding the role of bottom currents in the sedimentary evolution of the Spanish and Moroccan continental margins and adjacent basins during the Pliocene and Quaternary. This study was conducted using swath bathymetry data, more than 1900 profiles consisting of parametric, single- and multi-channel seismic records, scientific and commercial wells, sediment cores, and hydrographic data comprising: Conductivity, Temperature and Depth (CTD) profiles, Acoustic Doppler Current (ADCP) profiles, and EK60 echograms. Here, for the first time, a morphosedimentary scenario with a wide spectrum of depositional (plastered, sheeted, channel-related, mounded confined, elongated and separated drifts) and erosional (terraces, escarpments, moats, channels and furrows) contourite features are described in the Alboran Sea, from the shelf break to the basin floor. Hydrographic data offers new insights into the distribution of the Mediterranean water masses, and reveals that the bottom circulation of the Western Intermediate Water (WIW) and the Levantine Intermediate Water (LIW) interact with the Spanish slope, and the Western Mediterranean Deep Water (WMDW) with the Moroccan slope, Spanish baseof- slope and deep basins. The integration of distinct datasets and approaches allow a new sedimentary model to be proposed for the Alboran Sea that underlines the significance of bottom current processes in shaping deep-sea morphology. This model suggests that the bottom circulation of water masses governs physiography, that the interface positions of water-masses with contrasting densities sculpt terraces at a regional scale, and that morphological obstacles play an essential role in the local control of processes and watermass distribution. An analysis of the seismic stratigraphy from the Pliocene and Quaternary sequences has enabled to update and rename the stratigraphic boundaries and establish a new seismic stratigraphy for the Alboran Sea, after relocating the base of the Quaternary from 1.8 to 2.6Ma. Additionally, the seismic analysis involves the presentation and discussion of the evidence for contourite features reaching the scale of the Alboran Basin. Contourite drifts (plastered, sheeted, elongated separated and confined mounded drifts) and erosive features (terraces, escarpments, moats, channels, furrows) were developed under the continuous influence of Mediterranean water masses after the opening of the Strait of Gibraltar (~5.33Ma). At least two primary factors have controlled the contourite features 12 in this sea: i) tectonics, which has governed the relocation of the main Mediterranean flow pathways and their circulation patterns; and ii) climate, which has influenced both watermass conditions (depth and density contrast of the interfaces) and hinterland sediment sources, conditioning the morphoseismic expression and growth pattern of drifts and terrace formation (dimensions). The distribution of contourite features through time and space allows to propose three main scenarios for ocean circulation since the opening of the Strait of Gibraltar: i) Atlantic Zanclean flooding; ii) the Pliocene sea, with two different stages for the dense circulation and characterised by poorly-defined and unstable interfaces for the Atlantic Waters (AW), light and dense Mediterranean waters and the presence of a strong countercurrent in the Western Basin; and iii) the Quaternary sea, characterised by tabular Mediterranean water masses with multiple current dynamics, increasingly important density contrasts, and climate shifts causing major vertical and horizontal displacement of the interfaces. These stages reflect variability in the bottom current regimes and related alongslope efficiency in terms of transport, deposition and erosion. The detailed seismic analysis of the units making up the Pliocene and Quaternary sequences allows for the first time, to make an in-depth analysis of the contourite features, turbidite systems and mass-movement deposits, and map them through time. These maps are enormously helpful when it comes to understanding the sedimentary architecture of the Spanish and Moroccan continental margins and basins, as well as for decoding the palaeoceanographic processes from a geological perspective. Two main contourite depositional systems are defined: the Intermediate Contourite Depositional System (ICDS), formed under the action of the Light Mediterranean Waters (LMW) on the Spanish margin, and the Deep Contourite Depositional System (DCMW), formed under the action of the Dense Mediterranean Waters (DMW) mainly on the Moroccan margin and basins. The characterisation of the terraces as contourite features that form under the combination of two water masses, has also led to the definition of the Atlantic Contourite Depositional System (ACDS). The occurrence of several contourite depositional systems has led to the suggestion of a new term, not heretofore considered in the literature: Multiple Contourite Depositional System (MCDS), which refers to the set of different CDSs that occurs in the same area and evolving under the action of multiple water masses. In addition, twenty turbidite systems have been characterised, revealing that they are responsible for the different sedimentary architecture of the Spanish margin, where they coexist with contourites, as on the Moroccan margin the turbidite systems are less well developed. The mass-movement deposits are mainly related to the reworking of the contourites draping the highs. Mainly contourites but also turbidites, allowed to define from a geological 13 perspective the basic oceanographic processes and to determine their occurrence, relative magnitude and energy, and time of action. This PhD thesis also explains the uneven development of the turbidite systems in the Alboran Sea, which is interpreted to be conditioned by the interaction of alongslope with downslope processes. Several morphological and sedimentary signatures produced by the interaction between both processes have been identified in the Pliocene and Quaternary records, as well as on the present-day seafloor of the Alboran Sea. The interaction scenarios move between two-end-members: from bottom currents dominating gravity flows to gravity flows dominating contour currents. In between these extreme cases, the alternation and mutual influence of both processes can occur. Two different conceptual models of interaction are proposed for the Spanish and Moroccan margins. i) On the Spanish margin, the alongslope and downslope interaction is especially complex and varied, with both regional and local effects on the turbidite systems. This is because here the turbidite systems are influenced at different water depths by Atlantic and Mediterranean water masses and their interfaces, with current flows that change acrossand downslope. ii) On the Moroccan margin, the vigorous action of the WMDW primarily inhibits the formation of canyons and associated deposits. The findings of this PhD thesis suggest that the relevance of bottom-water processes in deep sea must be reevaluated. It is concluded that understanding the influence of bottom currents is not only essential for reconstructing present and past water mass circulation, but also for recognising sea floor morphologies and decoding the sedimentary stacking pattern and evolution of deposits, as well as global climate and periods of eustatic variation.
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Brussaard C.P.D., K.D. Bidle, C. Pedrós-Alió, C. Legrand
Nature Reviews Microbiology, 2, 16255, 1-2. DOI: 10.1038/nmicrobiol.2016.255 (BibTeX: brussaard.etal.2016a)
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García Sotillo M., E. Garcia-Ladona, A. Orfila, P. Rodríguez-Rubio, J. Cristobal Maraver, D. Conti, E. Padorno, J.A. Jiménez, E. Capó, F. Pérez, J.M. Sayol, F.J. de los Santos, A. Amo, A. Rietz, C. Troupin, J. Tintore, E. Álvarez-Fanjul
Earth System Science Data, 8, 1, 141-149. DOI: 10.5194/essd-8-141-2016 (BibTeX: garciasotillo.etal.2016c)
Resum: Veure
On 9 September 2014, an intensive drifter deployment was carried out in the Strait of Gibraltar. In the frame of the MEDESS-4MS Project (EU MED Program), the MEDESS-GIB experiment consisted of the deployment of 35 satellite tracked drifters, mostly of CODE-type, equipped with temperature sensor sampling at a rate of 30 min. Drifters were distributed along and on both sides of the Strait of Gibraltar. The MEDESS-GIB deployment plan was designed as to ensure quasi-synoptic spatial coverage. To this end, four boats covering an area of about 680 NM2 in 6 h were coordinated. As far as these authors know, this experiment is the most important exercise in the area in terms of number of drifters released. Collected satellite-tracked data along drifter trajectories have been quality controlled and processed to build the presented MEDESS-GIB database. This paper reports the MEDESS-GIB data set that comprises drifter trajectories, derived surface currents and in situ SST measurements collected along the buoys tracks. This series of data is available through the PANGAEA (Data Publisher for Earth and Environmental Science) repository, with the following doi:10.1594/PANGAEA.853701. Likewise, the MEDESS-GIB data will be incorporated as part of the Copernicus Marine historical products. The MEDESS-GIB data set provides a complete Lagrangian view of the surface inflow of Atlantic waters through the Strait of Gibraltar and thus, very useful data for further studies on the surface circulation patterns in the Alboran Sea, and their links with one of the most energetic Mediterranean Sea flows: the Algerian Current.
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Dallarés S., C.M. Moyà-Alcover, F. Padrós, J.E. Cartes, M. Solé, C. Castañeda, M. Carrassóna
Deep-Sea Research. Part I: Oceanographic Research Papers, 118, 84-100. DOI: 10.1016/j.dsr.2016.11.001 (BibTeX: dallares.etal.2016a)
Resum: Veure
The greater forkbeard Phycis blennoides is a benthopelagic fish distributed in the Mediterranean and NE Atlantic. The main goal of this study is to describe the complete parasite community of this species, which is at present unknown. A total of 188 specimens of P. blennoides were captured in the Balearic Sea (NW Mediterranean Sea) at 550–1250 m depth during the four seasons of 2007, in summer of 2010 and in summer and autumn of 2011 at five distinct localities off the mainland slope off Catalonia coasts and off the insular slope off the Balearic Islands. Environmental and fish biological, parasitological, dietary, enzymatic and histological data were obtained and the relationships among them tested. A total of 20 different parasites were recovered, of which 11 constitute new host records. The most important parasites were the monogenean Diclidophora phycidis, the digeneans Bathycreadium brayi and Lepidapedon spp., the nematodes Capillaria gracilis, Collarinema collaris, Cucullanus sp. and Hysterothylacium aduncum, and the copepod Clavella alata. Overall, the parasite community of P. blennoides was characterized by high abundance, richness and diversity. Significant differences in the structure of the parasite community were detected between samples from <1000 to >1000 m depth and between samples from off the mainland and insular slopes. Significant seasonal and/or geographical differences were found for some specific parasites. Abundance of the nematode C. collaris was associated to high levels of turbidity and O2 concentrations near the bottom. Abundances of H. aduncum, D. phycidis, B. brayi and Lepidapedon spp. were linked to high near-bottom temperature and salinity. Dietary analyses evidenced the role as potential intermediate hosts in parasite transmission by some prey (e.g. the teleost Gaidropsarus biscayensis for the cestode Grillotia cf. erinaceus and the nematodes Anisakis spp. or the euphausiid Meganyctiphanes norvegica for the acanthocephalan Echinorhynchus sp.). While the abundance of B. brayi, C. collaris, Cucullanus sp. and Echinorhynchus sp. was negatively linked to acetylcholinesterase activity (AChE), the abundance of Echinorhynchus sp. and H. aduncum correlated positively with lipid peroxidation levels. Cysts of unknown etiology in fish gills were detected at higher prevalence than in any other fish from the same area. Number and area of hepatic macrophage centres varied significantly among seasonal and geographical groups and seemed not significantly influenced by parasite infection levels.
Paraules clau: Phycis blennoides, parasites, diet, biomarkers, deep-sea, Mediterranean
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Chaparro D., J. Vayreda, M. Vall-llossera, M. Banqué, M. Piles, A. Camps, J. Martínez-Vilalta
IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, 99, 1--12. DOI: 10.1109/JSTARS.2016.2585505 (BibTeX: chaparro.etal.2016c)
Resum: Veure
Increased intensity and duration of droughts and high temperature events have been associated with forest decline in many parts of the world, and these decline events are expected to become more common under climate change. There is therefore a need for monitoring and modelling of forest decline. We used a regional forest condition monitoring program (DEBOSCAT) to study the spatial distribution of decline events in 2012 in Catalonia (Northeastern Spain) and their relationship with climatic factors. In 2012, this dataset was collected after an extraordinarily dry summer, and allowed the study of decline events in eight dominant tree species. We fitted a logistic model to predict forest decline probability as a function of species, precipitation and temperature anomalies, solar radiation, and remotely sensed soil moisture data from the Soil Moisture and Ocean Salinity (SMOS) mission. Broadleaved species were more affected by decline events than conifers. The statistical model explained almost 40% of forest decline occurrence, wherein almost 50% of this variability was explained by species effect, with broadleaved trees being generally more sensitive to the studied factors than conifers. Climatically wetter areas and those more exposed to radiation were more likely to be affected, suggesting better adaptation of forests in dry areas. In general, more damaged forests were characterized by high positive temperature anomalies, lower than average rainfall, and low soil moisture in summer 2012. The most vulnerable species was Fagus sylvatica, a Euro-Siberian species, contrasting with Pinus halepensis, a typically Mediterranean species, which showed low sensitivity to drought.
Paraules clau: Forest decline; Drought; Temperature anomalies; SMOS; Soil moisture; Regional scale; Predictive modelling; Forest monitoring; Climate change
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Solé J., J. Ballabrera-Poy, D. Macías, I.A. Catalán
Scientia Marina, 80S1, 249-256. DOI: http://dx.doi.org/10.3989/scimar.04290.04A (BibTeX: sole.etal.2016g)
Resum: Veure
In this work we focus on the Alboran Sea (western Mediterranean) to relate wind field and ocean velocity variability with chlorophyll a (Chl a) behaviour, using a 2-km resolution, coupled 3D ocean circulation-NPZD model (ROMS). The analysis is done in three steps. First, we split the seasonal and residual contribution for the fields under study. Second, we calculate the corresponding empirical orthogonal functions (EOFs) for the seasonal and residual parts. Finally, we relate each pair of variables for both seasonal and residual contribution EOFs. The results reported here allow the links between wind and Chl a to be quantified. We explain these links in terms of the ocean velocity field acting as a driver of Chl a variability. The results show that, although the seasonal part of the Chl a field is modulated by the vertical velocity, the residual component is modulated by the horizontal velocity components. Vertical velocities are responsible, through coastal upwelling, for Chl a bloom enhancement, while horizontal velocities spread coastal Chl a surface blooms off-shore.
Paraules clau: Keywords: Alboran Sea; chlorophyll; wind forcing; primary production; ocean biogeochemical model; ROMS model; EOF analysis
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Pelegrí J.L., C. Gabarró, A. Camps
Scientia Marina, 80S1, 15-24. (BibTeX: pelegri.etal.2016c)
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García-Ladona E., J. Salvador, P. Fernández, J.L. Pelegrí, P. Elósegui, O. Sánchez, J.A. Jiménez, F. Pérez, J. Ballabrera, J. Isern-Fontanet, J. Salat, J. Font
Scientia Marina, 80S1, 141-158. DOI: 10.3989/scimar.04325.14A (BibTeX: garcialadona.etal.2016d)
Resum: Veure
Since the mid-1980s, physical oceanographers at the Institute of Marine Sciences have been involved in the use of Lagrangian drifters as a complementary technology for their oceanographic research. As Lagrangian observations became more feasible, these researchers continued developing their own drifters in what was to be the seed of current technological activities at the Physical and Technological Oceanography Department. In this paper we overview the work done during the last 30 years with special focus on Lagrangian developments from the initial activities to the latest developments. In addition to basic oceanography research applications, Lagrangian technological developments include prototypes for measuring surface and subsurface ocean properties, for tracking purposes in search and rescue operations and pollution events, and for monitoring ice motion and thickness in the Arctic. The paper emphasizes original and unpublished technical aspects related to the latest developments.
Paraules clau: Lagrangian drifters; sea surface measurements; salinity measurements; oil spills drifters; SMOS.
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Piles M., G. Petropoulos, N. Sánchez, A. González-Zamora, G. Ireland
Remote Sensing of Environment, 180, 403-417. DOI: 10.1016/j.rse.2016.02.048 (BibTeX: piles.etal.2016a)
Resum: Veure
Earth Observation (EO) technology is today at a maturity level that allows deriving operational estimates of Surface Soil Moisture (SSM) from a variety of sensors; yet, such products are provided at present at a coarse spatial and/or temporal resolution, which restricts their use in local or regional scale studies and practical applications. Herein, a methodology to derive SSMestimates fromspace at previously unattained spatio-temporal resolutions is proposed. The method is based on a variant of the “triangle” inversion technique leveraging on the strengths and synergies ofSMOS (SoilMoisture and Ocean Salinitymission)microwave observations and geostationary optical/infrared data. The SSMretrieval technique allows for: i) enhancing the spatial resolution of SMOS SSMproductestimates to 3 km spatial resolution, and, ii) providing a temporal average daytime SM product from the instantaneous fine-scale SSMestimates acquired every 15min; the latter is allowing higher coverage in presence of clouds and representativeness (up to 96 estimates per day) in comparison to the instantaneous estimate at the time of satellite overpass.The proposed technique has been implemented to SMOS andMSG (Meteosat Second Generation) SEVIRI (Spinning Enhanced Visible and Infrared Imager) observations acquired over the Iberian Peninsula and Southern France during year 2011. SSM instantaneous estimates at the time of SMOS overpass and daytime-averaged SSM estimates have been obtained and evaluated separately against collocated in-situ measurements acquired froma total of 40 stations belonging to the REMEDHUS, VAS and SMOSMANIA permanent soilmoisturemeasurement networks. Statistical agreement between compared datasets has been evaluated both at individual stations and considering the network average on the basis of several statistical terms computed including correlation,bias, root-mean-squared errors, slope and intercept of linear regression. Results showed that the proposed method not only preserves the quality of SMOS SSMat finer spatial scales, but also allows achieving higher temporal coverage and representativeness in daytime averages. The synergy of SMOS and SEVIRI provides a pathway to enhance water cycle EO capabilities taking full advantage of the new observational records of SSM and operational geostationary information.
Paraules clau: Soil moisture SMOS MSG SEVIRI Synergy Downscaling Temporal resolution Spatial resolution
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Fernández-Álvarez F.Á., C.P.P. Martins, E.A.G. Vidal, R. Villanueva
Zoological Journal of the Linnean Society, DOI: 10.1111/zoj.12496 (BibTeX: fernandezalvarez.etal.2016)
Resum: Veure
Oceanic squids of the family Ommastrephidae are an important fishing resource worldwide. Although cumulative knowledge exists on their subadult and adult forms, little is known about their young stages. Their hatchlings are among the smaller cephalopod paralarvae. They are characterized by the fusion of their tentacles into a proboscis and are very difficult to identify to species level, especially in areas where more than one species coexist. Seven species are found in the north-east (NE) Atlantic. In this study, mature oocytes of Illex coindetii, Todarodes sagittatus and Todaropsis eblanae were fertilized in vitro to obtain and describe hatchlings. Full descriptions based on morphometric characters, chromatophore patterns, skin sculpture and the structure of proboscis suckers are provided based on live specimens. This information was combined with previous descriptions of paralarvae, not necessarily based on DNA or known parentage, from four other ommastrephid species distributed in the same area and a dichotomous key was developed for the identification of paralarvae of the NE Atlantic. The most useful taxonomic characters were: the relative size of the lateral and medial suckers of the proboscis, the presence/absence of photophores and the arrangement of pegs on the proboscis suckers. This key was successfully used to identify wild collected rhynchoteuthion paralarvae from the NE Atlantic. Reliable identification of wild paralarvae can foster a better understanding of the population dynamics and life cycles of ommastrephid squids.
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Albo-Puigserver M., J. Navarro, M. Coll, C.A. Layman, I. Palomera
Journal of Sea Research, 117, 27-35. DOI: 10.1016/j.seares.2016.09.003 (BibTeX: albopuigserver.etal.2016a)
Resum: Veure
Ecological knowledge of food web interactions within pelagic marine communities is often limited, impairing our capabilities to manage these ecologically and economically important marine fish species. Here we used stable isotope analyses to investigate trophic interactions in the pelagic ecosystem of the northwestern Mediterranean Sea during 2012 and 2013. Our results suggest that European sardine, Sardina pilchardus, and anchovy, Engraulis encrasicolus, are consumers located at relatively low levels of the pelagic food web. Unexpectedly, the round sardinella, Sardinella aurita, appeared to be located at a higher trophic level than the other small pelagic fish species, although previous studies found similarity in their diets. Isotope data suggested that trophic niches of species within the genera Trachurus spp. and Scomber spp., were distinct. Atlantic bonito Sarda sarda, European hake Merluccius merluccius and European squid Loligo vulgaris, appeared to feed at higher trophic levels than other species. Despite some intraspecific seasonal variability for some species, community trophic structure appeared relatively stable through the year. These data provide an important step for developing models of food web dynamics in the northwestern Mediterranean Sea.
Paraules clau: Stable isotopes, Pelagic fish, Isotopic niche, Food web, Community structure, Seasonal, Trophic segregation
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Amato A., S. Fortini, R. Watteaux, M. Diano, S. Espa, S. Esposito, M.I. Ferrante, F. Peters, D. Iudicone, M. Ribera d’Alcalà
Review of Scientific Instruments, 87, 035119, DOI: 10.1063/1.4944813 (BibTeX: amato.etal.2016)
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Dallarés S.,
PhD thesis. Director/es: M. Carrasson, F. Padrós, M. Solé, Montserrat. (BibTeX: dallares.2016a)
Resum: Veure
The Mediterranean deep-sea remains mostly unexplored and, specifically, the parasite communities of Mediterranean deep-dwelling fishes are largely unknown. Parasites are known to be effective bioindicators. Because many of them are trophically-transmitted and show complex life cycles involving more than one host, parasites can reflect host feeding habits, trophic interactions and species composition of their ecosystems. Parasites can also reveal environmental changes of anthropogenic or natural origin, and respond to environmental conditions that may influence their own biology or their hosts’ population dynamics. Furthermore, the differentiation of parasite communities across geographical gradients allows their use as discrimination tags of host populations. [...]
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Galiana S.,
PhD thesis. Director/es: X. García Martínez. Barcelona. (BibTeX: galiana.2016a)
Resum: Veure
The controlled-source electromagnetics (CSEM) and magnetotellurics (MT) methods are common geophysical tools for imaging the electrical properties of the Earth’s subsurface and are employed independently, jointly, and in combination with other geophysical techniques for this purpose. In order to appreciate measured data, both methods require forward and inverse modeling of the electrically conductive subsurface to the end that the modeled data reasonably fits the observations. Naturally, the potential goodness of this fit not only depends on the error in the measured data but also on the degree of physical approximation inferred by numerical modeling. Therefore, active research focuses on new methods for modeling and inversion to obtain accurate and reliable models of the Earth’s structure in increasingly complex scenarios. [...]
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Kiendler-Scharr A., A.A. Mensah, E. Friese, D. Topping, E. Nemitz, A.S.H. Prevot, M. Aijala, J. Allan, F. Canonaco, M. Canagaratna, S. Carbone, M. Crippa, M. Dall Osto, D.A. Day, P. De Carlo, C.F. Di Marco, H. Elbern, A. Eriksson, E. Freney, L. Hao, H. Herrmann, L. Hildebrandt, R. Hillamo, J.L. Jimenez, A. Laaksonen, G. McFiggans, C. Mohr, C. O\'Dowd, R. Otjes, J. Ovadnevaite, S.N. Pandis, L. Poulain, P. Schlag, K. Sellegri, E. Swietlicki, P. Tiitta, A. Vermeulen, A. Wahner, D. Worsnop, H.C. Wu
Geophysical Research Letters, 43, 7735-7744. DOI: 10.1002/2016GL069239 (BibTeX: kiendlerscharr.etal.2016)
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Grieco G., F. Nirchio, A. Montuori, M. Migliaccio, W. Lin, M. Portabella
Proceedings of the ESA Living Planet Symposium 2016, 9 - 13 May 2016, Prague, Czech Republic, ESA SP-740 (DVD), . (BibTeX: grieco.etal.2016a)
Resum: Veure
The dependency of the azimuth wavelength cut-off on the wind speed has been studied through a dataset of Sentinel-1 multi look SAR images co-located with wind speed measurements, significant wave height and mean wave direction from ECMWF operational output. A Geophysical Model Function (GMF) has been fitted and a retrieval exercise has been done comparing the results to a set of independent wind speed scatterometer measurements of the Chinese mission HY-2A. The preliminary results show that the dependency of the azimuth cut-off on the wind speed is linear only for fully developed sea states and that the agreement between the retrieved values and the measurements is good especially for high wind speed. A similar approach has been used to assess the dependency of the azimuth cut-off also for X-band COSMO-SkyMed data. The dataset is still incomplete but the preliminary results show a similar trend.
Morganti T., G. Yahel, M. Ribes, R. Coma
Journal of Visualized Experiments, 114, DOI: 10.3791/54221 (BibTeX: morganti.etal.2016)
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Alcaraz M., A. Calbet, S. Isari, X. Irigoien, I. Trepat, E. Saiz
Scientia Marina, 80, S1, 79-87. DOI: 10.3989/scimar.04353.15A (BibTeX: alcaraz.etal.2016a)
Resum: Veure
The temporal and spatial changes of zooplankton and chlorophyll a concentration were studied during the warm stratification period (early June) at three stations whose traits corresponded to the coastal, frontal, and offshore-dome water conditions described for the Catalan Sea. We sampled the stations for 12 days at a frequency ranging from less than 10 to 102 h, with a spatial resolution ranging from 10 to 104 m. The objective was to determine the variability of mesozooplankton and phytoplankton (chlorophyll a) biomass, and average individual size (mass) across a coast-offshore transect in relation to the stratification conditions prevailing in the NW Mediterranean during summer. The vertical distribution of phytoplankton biomass displayed a clear deep maximum at 60 m depth except at the coastal station. This maximum exists during most of the year and is especially important during the density stratification period. It was accompanied during daylight hours by a coherent zooplankton maximum. At sunset mesozooplankton ascended and dispersed, with larger organisms from deeper layers joining the migrating community and increasing the average individual mass. The highest variability of mesozooplankton biomass, individual mass and chlorophyll a concentration occurred at the front station due to the coupling between the vertical migration of zooplankton and the particular characteristics of the front. According to the data shown, the highest variability was observed at the lowest scales.
Paraules clau: Zooplankton biomass, NW Mediterranean, spatial distribution, short-term variability, biomasa de zooplankton, Mediterráneo noroccidental, distribución espacial, variabilidad de corto plazo
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Bellés-Garulera J., M. Vila, E. Borrull, P. Riobó, J.M. Franco, M.M. Sala
Scientia Marina, 80, S1, 97-106. DOI: 10.3989/scimar.04405.01A (BibTeX: bellesgarulera.etal.2016a)
Resum: Veure
Vibrios include several pathogenic bacteria that occur in aquatic environments. The presence of Vibrio has been assessed in many ecosystems by culture-based techniques. However, little is known on the contribution of vibrios in the sea, especially in areas subject to harmful algal blooms. A preliminary study in Sant Andreu de Llavaneres beach (NW Mediterranean) showed the presence of some Vibrio species during a recurrent bloom of the harmful benthic dinoflagellate Ostreopsis cf. ovata. In order to establish the importance of vibrios in a coastal area of the NW Mediterranean and to study the association with the dinoflagellate, we conducted a sampling monitoring for one year to quantify the concentration of vibrios both in the water (free-living and attached to particles) and in the epiphytic community of macroalgae. The aims were 1) to evaluate the relative abundance of Vibrio in the epiphytic and in the planktonic bacterial community, 2) to assess the percentage of free-living and attached vibrios in the planktonic community, and 3) to determine whether the presence of vibrios is associated with the blooms of the toxic dinoflagellate Ostreopsis or with other environmental parameters. For this purpose, a CARD-FISH molecular probe was applied for the specific detection of bacteria belonging to the genus Vibrio. Cells were quantified and the abundance of both particles and bacteria attached to particles were assessed. The maximum Vibrio concentration (1.3x104 cells ml–1 and 1.4x106 cells g–1 FW, for planktonic and epiphytic samples, respectively) was detected in September. Free-living vibrios contributed 0.38±0.24% to the total free-living planktonic community and 1.12±0.28% to the epiphytic bacterial community. However, their contribution was particularly high in the planktonic community attached to particles (17.37±20.49%). Although in the planktonic community Vibrio was found preferentially free-living (82.63±20.01%), particles are a niche for vibrios, since in particles vibrios may represent up to 72% of the total attached bacterial community. Abundance of planktonic Vibrio was correlated with Ostreopsis concentration and it is likely that they play a role in the wound infections suffered by beach users during the bloom.
Paraules clau: Vibrio, bacteria, particles, Mediterranean, HAB, dinoflagellates, bacterias, partículas, dinoflagelados
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Brines M., M. Dall\'Osto, F. Amato, M.C. Minguillon, A. Karanasiou, A. Alastuey, X. Querol
Atmospheric Chemistry and Physics, 16, 6785-6804. DOI: 10.5194/acp-16-6785-2016 (BibTeX: brines.etal.2016)
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Cabello A.M., M. Latasa, I. Forn, X.A.G. Morán, R. Massana
Environmental Microbiology, 18, 5, 1578-1590. DOI: 10.1111/1462-2920.13285 (BibTeX: .etal.2016c)
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Solé M., E. Mañanós, M. Blazquez
Marine Environmental Research, 117, 63-74. DOI: 10.1016/j.marenvres.2016.03.010 (BibTeX: sole.etal.2016a)
Resum: Veure
Specimens of Solea solea and Solea senegalenesis at different developmental stages were obtained from seven fishing grounds along the NW Mediterranean. Gonad development in males was classified into five stages, from early spermatogenesis to recovery, while four stages were considered in females, from growth to maturation. Vitellogenin (VTG) and sex steroid levels including an estrogen (estradiol, E2), two androgens (testosterone, T and 11-ketotestosterone, 11KT) and a progestin (17,20β-dihydroxy pregn-4-en-3-one, 17,20β-P or maturation inducing steroid, MIS) were analysed in plasma. Their levels were more clearly related to the developmental stage of the gonads than to the sampling site characteristics. In addition, enzyme activities in gonads, such as acetylcholinesterase (AChE) and carboxylesterase (CbE) were gender-dependent and higher in males than in females. Gonadal glutathione S-transferase (GST) activity was enhanced in the most anthropogenic impacted sites. VTG was absent in males and very low or undetectable in immature females, while mature females exhibited high VTG levels, clearly related to the gonado-somatic index. Sex steroid levels (ng/ml) varied in males and females regardless of the species. E2 levels in females ranged from 0.22 to 6.98 while in males ranged from 0.11 to 0.27. T varied from 0.12 to 0.93 in females and from 0.56 to 1.36 in males, while 11KT in females fluctuated from 0.03 to 0.57 and from 0.26 to 6.42 in males. Similarly, MIS in females ranged from 0.75 to 3.71 and from 1.12 to 5.61 in males. The lack of endocrine disturbances was confirmed by histological examination of the gonads. This study informs on basal sex hormone levels and enzyme activities during gonadal maturation of wild Solea spp. that can be useful in the identification and further remediation of possible pollution events.
Paraules clau: Solea spp., sex steroids, enzymatic activity, gonad development, endocrine disruption
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Romero E., J. Gamier, G. Billen, F. Peters, L. Lassaletta
Science of The Total Environment, 573, 420-432. DOI: 10.1016/j.scitotenv.2016.08.007 (BibTeX: romero.etal.2016c)
Resum: Veure
Nitrogen (N) retention sensu lato refers to all processes preventing new reactive nitrogen brought into watersheds through agricultural or industrial activities to be exported by river systems to the sea. Although such processes protect marine systems from the threat of eutrophication and anoxia, they raise other environmental issues, including the acidification of soils, the emission of ammonia and greenhouse gases, and the pollution of aquifers. Despite these implications, the factors involved in N retention are still poorly controlled, particularly in arid and semi-arid systems. The present study evaluates the N fluxes of 38 catchments in the Iberian Peninsula with contrasting climatic characteristics (temperate and Mediterranean), land uses, and water management practices. This diversity allows addressing the contribution of physical and socioecological factors in N retention, and more specifically, exploring the relation between N retention and water regulation. We hypothesise that the extreme flow regulation implemented in the Mediterranean enhances the high N retention values associated with arid and semi-arid regions. The results show that reservoirs and irrigation channels account for > 50% of the variability in N retention values, and above a certain regulation threshold, N retention peaks to values > 85–90%. Future climate projections forecast a decrease in rainfall and an increase in agricultural intensification and irrigation practices in many world regions, most notably in arid and semi-arid areas. Increased water demand will likely lead to greater flow regulation, and the situation in many areas may resemble that of Iberian Mediterranean catchments. High N retention and the associated environmental risks must therefore be considered and adequately addressed
Paraules clau: N retention, water regulation, reservoirs, irrigation, Mediterranean climate, river basin
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Olivar M.P., A. Sabatés, M.V. Pastor, J.L. Pelegrí
Deep-Sea Research. Part I: Oceanographic Research Papers, 117, 120-137. DOI: 10.1016/j.dsr.2016.10.003 (BibTeX: olivar.etal.2016b)
Resum: Veure
We explore the associations between larval fish assemblages and oceanographic conditions in the upper ocean (top 200 m) along the African slope, from tropical (15°N) to subtropical (35°N) latitudes, during a period of intense upwelling. In this extensive region, the northward Mauritanian Current and Poleward Undercurrent carry South Atlantic Central Waters (SACW) while the southward Canary Upwelling Current transports North Atlantic Central Waters (NACW). South of Cape Blanc we only find SACW, and north of Cape Blanc there is NACW far offshore and a combination of NACW and SACW nearshore, separated by the Canary Upwelling Front (CUF). The larvae of different myctophid species serve as indicators of the water masses, e.g. S. veranyi and M. punctatum were found in some coastal stations that were dominated by NACW, while the tropical mesopelagic B. argyrogaster, H. macrochir, M. affine and S. kreffti were associated to the SACW. The along-slope offshore convergence of NACW and SACW takes place at the Cape Verde Frontal Zone (CVFZ), representing a region of extensive offshore export for larvae of coastal species, S. pilchardus and E. encrasicolus, far from their nearshore spawning area. The large-scale frontal systems (CVFZ and CUF) and mesoscale eddies contribute to retain larvae within productive waters, influencing both coastal and oceanic species.
Paraules clau: Fish larvae, mesoscale hydrography, Canary upwelling, Cape Verde Frontal Zone, mesoscale eddies