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Auteur Chu, T.V.; Torréton, J.-P.; Mari, X.; Nguyen, H.M.T.; Pham, K.T.; Pham, T.T.; Bouvier, T.; Bettarel, Y.; Pringault, O.; Bouvier, C.; Rochelle-Newall, E.
Titre Nutrient ratios and the complex structure of phytoplankton communities in a highly turbid estuary of Southeast Asia Type Article scientifique
Année 2014 Publication Revue Abrégée Environ Monit Assess
Volume 186 Numéro 12 Pages (down) 8555-8572
Mots-Clés Hab; Phytoplankton diversity; Southeast Asia; vietnam
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Volume de collection Numéro de collection Edition
ISSN 0167-6369 ISBN Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 1161
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Auteur Tagliabue, A.; Barrier, N.; Du Pontavice, H.; Kwiatkowski, L.; Aumont, O.; Bopp, L.; Cheung, W.W.L.; Gascuel, D.; Maury, O.
Titre An iron cycle cascade governs the response of equatorial Pacific ecosystems to climate change Type Article scientifique
Année 2020 Publication Revue Abrégée Glob. Change Biol.
Volume 26 Numéro 11 Pages (down) 6168-6179
Mots-Clés 21st-century projections; climate change; communities; iron; marine ecosystems; metals; model; net primary production; ocean; phytoplankton; uncertainties
Résumé Earth System Models project that global climate change will reduce ocean net primary production (NPP), upper trophic level biota biomass and potential fisheries catches in the future, especially in the eastern equatorial Pacific. However, projections from Earth System Models are undermined by poorly constrained assumptions regarding the biological cycling of iron, which is the main limiting resource for NPP over large parts of the ocean. In this study, we show that the climate change trends in NPP and the biomass of upper trophic levels are strongly affected by modifying assumptions associated with phytoplankton iron uptake. Using a suite of model experiments, we find 21st century climate change impacts on regional NPP range from -12.3% to +2.4% under a high emissions climate change scenario. This wide range arises from variations in the efficiency of iron retention in the upper ocean in the eastern equatorial Pacific across different scenarios of biological iron uptake, which affect the strength of regional iron limitation. Those scenarios where nitrogen limitation replaced iron limitation showed the largest projected NPP declines, while those where iron limitation was more resilient displayed little future change. All model scenarios have similar skill in reproducing past inter-annual variations in regional ocean NPP, largely due to limited change in the historical period. Ultimately, projections of end of century upper trophic level biomass change are altered by 50%-80% across all plausible scenarios. Overall, we find that uncertainties in the biological iron cycle cascade through open ocean pelagic ecosystems, from plankton to fish, affecting their evolution under climate change. This highlights additional challenges to developing effective conservation and fisheries management policies under climate change.
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Volume de collection Numéro de collection Edition
ISSN 1354-1013 ISBN Médium
Région Expédition Conférence
Notes WOS:000572177100001 Approuvé pas de
Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2899
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Auteur Larras, F.; Rimet, F.; Gregorio, V.; Bérard, A.; Leboulanger, C.; Montuelle, B.; Bouchez, A.
Titre Pollution-induced community tolerance (PICT) as a tool for monitoring Lake Geneva long-term in situ ecotoxic restoration from herbicide contamination Type Article scientifique
Année 2016 Publication Revue Abrégée Environ Sci Pollut Res
Volume 23 Numéro 5 Pages (down) 4301-4311
Mots-Clés Atmospheric Protection/Air Quality Control/Air Pollution; Atrazine; Copper; Ecotoxicology; Environmental Chemistry; Environmental Health; Environment, general; Phytoplankton; Pollution-induced community tolerance (PICT); Restoration; Waste Water Technology / Water Pollution Control / Water Management / Aquatic Pollution
Résumé Chemical monitoring revealed a regular decrease in herbicide concentration in Lake Geneva since last decades that may be linked to an ecotoxic restoration of nontarget phytoplanktonic communities. The Pollution-induced community tolerance (PICT) approach was tested as a tool to monitor the ecotoxic restoration of Lake Geneva for herbicides from 1999 to 2011. We conducted monthly assessments in 1999 and in 2011 for the tolerance of the phytoplankton communities to two herbicides (atrazine and copper), using PICT bioassays. The taxonomical composition of the communities was determined on the same collecting dates. The herbicide concentration decrease during the 12 years significantly influenced the composition of communities. The PICT monitoring indicated that a significant tolerance decrease in the community to both herbicides accompanied the herbicide concentration decrease. PICT measurements for atrazine and copper also changed at the intra-annual level. These variations were mainly due to community composition shifts linked to seasonal phosphorus and temperature changes. PICT monitoring on a seasonal basis is required to monitor the mean tolerance of communities. PICT appeared to be a powerful tool that reflected the toxic effects on environmental communities and to monitor ecotoxic ecosystem restoration.
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ISSN 0944-1344, 1614-7499 ISBN Médium
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Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 1557
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Auteur Denis, M.; Thyssen, M.; Martin, V.; Manca, B.; Vidussi, F.
Titre Ultraphytoplankton basin-scale distribution in the eastern Mediterranean Sea in winter: link to hydrodynamism and nutrients Type Article scientifique
Année 2010 Publication Revue Abrégée Biogeosciences
Volume 7 Numéro 7 Pages (down) 2227-2244
Mots-Clés adriatic sea; community; cyanobacteria; general-circulation; nifh genes; phosphorus limitation; phytoplankton; pigment distribution; primary productivity; structure; unicellular; warm-core eddy
Résumé The basin-scale distribution of ultraphytoplankton (< 10 mu m) was determined in the upper 200 m of the eastern Mediterranean Sea during the winter season. Four clusters were resolved by flow cytometry on the basis of their optical properties and identified as Synechococcus, Prochlorococcus, pico- (< 3 mu m) and nanoeukaryotes (3-10 mu m). Synechococcus was the most abundant population (maximum abundance of about 37 000 cells cm(-3)) and contributed up to 67.7% to the overall ultraphytoplanktonic carbon biomass, whereas the contribution of Prochlorococcus never exceeded 6.5%. The maximum integrated carbon biomass was 1763, 453, 58 and 571 mg C m(-2) for nanoeukaryotes, picoeukaryotes, Prochlorococcus and Synechococcus respectively. Water mass properties were analyzed on the basis of temperature and salinity distributions in order to account for the general circulation and locate the main hydrodynamic structures (fronts, gyres, transition between western and eastern basins). The effect of the main hydrodynamic structures and nutrients on the ultraphytoplankton distribution was investigated. No positive correlation between nutrients and phytoplankton could be established when considering large scales. However, below 50 m depth, nutrient ratios between particular stations were correlated to corresponding density ratios. In contrast, significant relationships were found between Synechococcus abundance and density, resulting from the impact of a gyre in southern Adriatic basin and a thermohaline front in the Ionian basin. A significant relationship was also found between picoeukaryotes and salinity in the comparison of western and eastern Mediterranean Sea.
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Volume de collection Numéro de collection Edition
ISSN 1726-4170 ISBN Médium
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Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 914
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Auteur Amelineau, F.; Bonnet, D.; Heitz, O.; Mortreux, V.; Harding, A.M.A.; Karnovsky, N.; Walkusz, W.; Fort, J.; Gremillet, D.
Titre Microplastic pollution in the Greenland Sea: Background levels and selective contamination of planktivorous diving seabirds Type Article scientifique
Année 2016 Publication Revue Abrégée Environ. Pollut.
Volume 219 Numéro Pages (down) 1131-1139
Mots-Clés accumulation; Arctic; dovekies alle-alle; identification; ingestion; Little auk; marine debris; north-atlantic; pacific; Plastic; plastic-derived chemicals; Sea ice; Selective uptake; Size; vertical-distribution; Zooplankton
Résumé Microplastics have been reported everywhere around the globe. With very limited human activities, the Arctic is distant from major sources of microplastics. However, microplastic ingestions have been found in several Arctic marine predators, confirming their presence in this region. Nonetheless, existing information for this area remains scarce, thus there is an urgent need to quantify the contamination of Arctic marine waters. In this context, we studied microplastic abundance and composition within the zooplankton community off East Greenland. For the same area, we concurrently evaluated microplastic contamination of little auks (Alle alle), an Arctic seabird feeding on zooplankton while diving between 0 and 50 m. The study took place off East Greenland in July 2005 and 2014, under strongly contrasted sea-ice conditions. Among all samples, 97.2% of the debris found were filaments. Despite the remoteness of our study area, microplastic abundances were comparable to those of other oceans, with 0.99 +/- 0.62 m(-3) in the presence of sea-ice (2005), and 2.38 +/- 1.11 m(-3) in the nearby absence of sea-ice (2014). Microplastic rise between 2005 and 2014 might be linked to an increase in plastic production worldwide or to lower sea -ice extents in 2014, as sea-ice can represent a sink for microplastic particles, which are subsequently released to the water column upon melting. Crucially, all birds had eaten plastic filaments, and they collected high levels of microplastics compared to background levels with 9.99 and 8.99 pieces per chick meal in 2005 and 2014, respectively. Importantly, we also demonstrated that little auks took more often light colored microplastics, rather than darker ones, strongly suggesting an active contamination with birds mistaking microplastics for their natural prey. Overall, our study stresses the great vulnerability of Arctic marine species to microplastic pollution in a warming Arctic, where sea-ice melting is expected to release vast volumes of trapped debris. (C) 2016 Elsevier Ltd. All rights reserved.
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Editeur Lieu de Publication Éditeur
Langue English Langue du Résumé Titre Original
Éditeur de collection Titre de collection Titre de collection Abrégé
Volume de collection Numéro de collection Edition
ISSN 0269-7491 ISBN Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 1716
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