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Auteur Arones, K.; Grados, D.; Ayon, P.; Bertrand, A.
Titre Spatio-temporal trends in zooplankton biomass in the northern Humboldt current system off Peru from 1961-2012 Type Article scientifique
Année 2019 Publication Revue Abrégée Deep-Sea Res. Part II-Top. Stud. Oceanogr.
Volume 169 Numéro Pages Unsp-104656
Mots-Clés anchovy engraulis-ringens; chile; current ecosystem; Decadal trends; diet; Macrozooplankton; Mesozooplankton; Regime-shift; sardine; Secondary production; Spatiotemporal distribution; volume; zone
Résumé Anchovy (Engraulis ringens) is the most important exploited fish species in the Northern Humboldt Current System (NHCS) off Peru. This species, as well as most other pelagic resources, mainly forage on zooplankton. The NHCS is bottom-up controlled at a variety of scales. Therefore, fish biomass is driven by the abundance of their prey. In this context, we studied the spatiotemporal patterns of zooplankton biomass in the NHCS from 1961-2012. Data were collected with Hensen net all along the Peruvian coast. To transform zooplankton biovolume into biomass we used a regression that was calibrated from 145 zooplankton samples collected during four surveys and, for which, precise information was available on both biovolume and wet weight. The regression model was then applied on a time-series encompassing 158 cruises performed by the Peruvian Institute of the Sea (IMARPE) between 1961 and 2012. We observed a clear multidecadal pattern and two regime shifts, in 1973 and 1992. Maximum biomass occurred between 1961 and 1973 (61.5 g m(-2)). The lowest biomass (17.8 g m(-2)) occurred between 1974 and 1992. Finally, the biomass increased after 1993 (26.6 g m(-2)) but without reaching the levels observed before 1973. A seasonal pattern was observed with significantly more biomass in spring than in other seasons. Spatially, zooplankton biomass was higher offshore and in northern and southern Peru. Interestingly, the zooplankton sampling was performed using classic zooplankton net that are well fitted to mesozooplankton and are known to underestimate the macrozooplankton; however, the spatiotemporal patterns we observed are consistent with those of macrozooplankton, in particular euphausiids. This suggests that in the NHCS, when and where macrozooplankton dominates it also dominates the biomass obtained using classic zooplankton net samples. Finally, until now, in the NHCS only time-series on zooplankton biovolume were available. The biomass data we provide are more directly usable in trophic or end-to-end models.
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Langue English Langue du Résumé Titre Original
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Volume de collection Numéro de collection Edition
ISSN 0967-0645 ISBN Médium
Région Expédition Conférence
Notes WOS:000504782200009 Approuvé (up) pas de
Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2693
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Auteur Lopez-Joven, C.; Rolland, J.-L.; Haffner, P.; Caro, A.; Roques, C.; Carré, C.; Travers, M.-A.; Abadie, E.; Laabir, M.; Bonnet, D.; Destoumieux-Garzón, D.
Titre Oyster Farming, Temperature, and Plankton Influence the Dynamics of Pathogenic Vibrios in the Thau Lagoon Type Article scientifique
Année 2018 Publication Revue Abrégée Front. Microbiol.
Volume 9 Numéro Pages
Mots-Clés bivalve mollusks; mortality outbreak; Phytoplankton; Shellfish farming; Vibrio; Zooplankton
Résumé Vibrio species have been associated with recurrent mass mortalities of juvenile oysters Crassostrea gigas threatening oyster farming worldwide. However, knowledge of the ecology of pathogens in affected oyster farming areas remains scarce. Specifically, there are no data regarding (i) the environmental reservoirs of Vibrio populations pathogenic to oysters, (ii) the environmental factors favoring their transmission, and (iii) the influence of oyster farming on the persistence of those pathogens. This knowledge gap limits our capacity to predict and mitigate disease occurrence. To address these issues, we monitored Vibrio species potentially pathogenic to C. gigas in 2013 and 2014 in the Thau Lagoon, a major oyster farming region in the coastal French Mediterranean. Sampling stations were chosen inside and outside oyster farms. Abundance and composition of phyto-, microzoo-, and mesozooplankton communities were measured monthly. The spatial and temporal dynamics of plankton and Vibrio species were compared, and positive correlations between plankton species and vibrios were verified by qPCR on isolated specimens of plankton. Vibrio crassostreae was present in the water column over both years, whereas Vibrio tasmaniensis was mostly found in 2013 and Vibrio aestuarianus was never detected. Moreover, V. tasmaniensis and V. crassostreae were found both as free-living or plankton-attached vibrios one month after spring mortalities of the oyster juveniles. Overall, V. crassostreae was associated with temperature and plankton composition, whereas V. tasmaniensis correlated with plankton composition only. The abundance of Vibrio species in the water column was similar inside and outside oyster farms, suggesting important spatial dispersion of pathogens in surrounding areas. Remarkably, a major increase in V. tasmaniensis and V. crassostreae was measured in the sediment of oyster farms during cold months. Thus, a winter reservoir of pathogenic vibrios could contribute to their ecology in this Mediterranean shellfish farming ecosystem.
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Langue English Langue du Résumé Titre Original
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Volume de collection Numéro de collection Edition
ISSN 1664-302x ISBN Médium
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Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2438
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Auteur Ramirez-Romero, E.; Molinero, J.C.; Paulsen, M.; Javidpour, J.; Clemmesen, C.; Sommer, U.
Titre Quantifying top-down control and ecological traits of the scyphozoan Aurelia aurita through a dynamic plankton model Type Article scientifique
Année 2018 Publication Revue Abrégée J. Plankton Res.
Volume 40 Numéro 6 Pages 678-692
Mots-Clés 2 hydromedusae; annual cycle; baltic sea; coastal ecosystem; common jellyfish; ctenophore mnemiopsis-leidyi; jellyfish; kiel-bight; planktonic food web; population modeling; population-dynamics; predation impact; sarsia-tubulosa; stage-resolved model; zooplankton
Résumé Aurelia aurita (Linneaus, 1758) is a cosmopolitan scyphozoan, probably the most investigated jellyfish in temperate and highly productive coastal ecosystems. Despite a prominent top-down control in plankton food webs, a mechanistic understanding of A. aurita population dynamics and trophic interactions has been barely addressed. Here we develop a food web dynamic model to assess A. aurita role in the seasonal plankton dynamics of the Kiel Fjord, southwestern Baltic Sea. The model couples low trophic level dynamics, based on a classical Nutrient Phytoplankton Zooplankton Detritus (NPZD) model, to a stage-resolved copepod model (referencing Pseudocalanus sp.) and a jellyfish model (A. aurita ephyra and medusa) as consumers and predators, respectively. Simulations showed the relevance of high abundances of A. aurita, which appear related with warm winter temperatures, promoting a shift from a copepod-dominated food web to a ciliate and medusa dominated one. The model captured the intraspecific competition triggered by the medusae abundance and characterized by a negative relationship between population density and individual size/weight. Our results provide a mechanistic understanding of an emergent trait such as size shaping the food web functioning, driving predation rates and population dynamics of A. aurita, driving its sexual reproductive strategy at the end of the pelagic phase.
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Langue English Langue du Résumé Titre Original
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Volume de collection Numéro de collection Edition
ISSN 0142-7873 ISBN Médium
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Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2476
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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 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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Langue English Langue du Résumé Titre Original
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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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Auteur Pagano, M.; Sagarra, P.-B.; Champalbert, G.; Bouvy, M.; Dupuy, C.; Thomas, Y.; Charpy, L.
Titre Metazooplankton communities in the Ahe atoll lagoon (Tuamotu Archipelago, French Polynesia): Spatiotemporal variations and trophic relationships Type Article scientifique
Année 2012 Publication Revue Abrégée Marine Pollution Bulletin
Volume 65 Numéro 10–12 Pages 538-548
Mots-Clés Atoll lagoon; French Polynesia; Metazooplankton; Spatio-temporal patterns; Trophic relationships; pearl oyster
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Volume de collection Numéro de collection Edition
ISSN 0025-326x ISBN Médium
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Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 693
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