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Auteur (up) 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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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 (up) Annasawmy, P.; Ternon, J.-F.; Cotel, P.; Cherel, Y.; Romanov, E.; Roudaut, G.; Lebourges-Dhaussy, A.; Menard, F.; Marsac, F.
Titre Micronekton distributions and assemblages at two shallow seamounts of the south-western Indian Ocean: Insights from acoustics and mesopelagic trawl data Type Article scientifique
Année 2019 Publication Revue Abrégée Prog. Oceanogr.
Volume 178 Numéro Pages 102161
Mots-Clés Acoustics; deep-scattering layer; diel migration; fish aggregations; mesoscale features; Micronekton; mozambique channel; myctophid fishes; pelagic communities; Seamount; Seamount-associated fauna; South-western Indian Ocean; species identification; target strength; vertical-distribution
Résumé Micronekton distributions and assemblages were investigated at two shallow seamounts of the south-western Indian Ocean using a combination of trawl data and a multi-frequency acoustic visualisation technique. La Pa rouse seamount (summit depth similar to 60 m) is located on the outskirts of the oligotrophic Indian South Subtropical Gyre (ISSG) province with weak mesoscale activities and low primary productivity all year round. The “MAD-Ridge” seamount (thus termed in this study; similar to 240 m) is located in the productive East African Coastal (EAFR) province with high mesoscale activities to the south of Madagascar. Higher micronekton species richness was recorded at MAD-Ridge compared to La Perouse. Resulting productivity at MAD-Ridge seamount was likely due to the action of mesoscale eddies advecting productivity and larvae from the Madagascar shelf rather than local dynamic processes such as Taylor column formation. Mean micronekton abundance/biomass, as estimated from mesopelagic trawl catches, were lower over the summit compared to the vicinity of the seamounts, due to net selectivity and catchability and depth gradient on micronekton assemblages. Mean acoustic densities in the night shallow scattering layer (SSL: 10-200 m) over the summit were not significantly different compared to the vicinity (within 14 nautical miles) of MAD-Ridge. At La Perouse and MAD-Ridge, the night and day SSL were dominated by common diel vertically migrant and non-migrant micronekton species respectively. While seamount-associated mesopelagic fishes such as Diaphus suborbitalis (La Perouse and MAD-Ridge) and Benthosema fibula= performed diel vertical migrations (DVM) along the seamounts' flanks, seamount-resident benthopelagic fishes, including Cookeolus japonicus (MAD-Ridge), were aggregated over MAD-Ridge summit. Before sunrise, mid-water migrants initiated their vertical migration from the intermediate to the deep scattering layer (DSL, La Perouse: 500-650 m; MAD-Ridge: 400-700 m) or deeper. During sunrise, the other taxa contributing to the night SSL exhibited a series of vertical migration events from the surface to the DSL or deeper until all migrants have reached the DSL before daytime. Possible mechanisms leading to the observed patterns in micronekton vertical and horizontal distributions are discussed. This study contributes to a better understanding of how seamounts influence the DVM, horizontal distribution and community composition of micronekton and seamount-associated/resident species at two poorly studied shallow topographic features in the south-western Indian Ocean.
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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 0079-6611 ISBN Médium
Région Expédition Conférence
Notes WOS:000496861900013 Approuvé pas de
Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2666
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Auteur (up) Brophy, D.; Haynes, P.; Arrizabalaga, H.; Fraile, I.; Fromentin, J.-M.; Garibaldi, F.; Katavic, I.; Tinti, F.; Karakulak, F.S.; Macias, D.; Busawon, D.; Hanke, A.; Kimoto, A.; Sakai, O.; Deguara, S.; Abid, N.; Santos, M.N.
Titre Otolith shape variation provides a marker of stock origin for north Atlantic bluefin tuna (Thunnus thynnus) Type Article scientifique
Année 2016 Publication Revue Abrégée Mar. Freshw. Res.
Volume 67 Numéro 7 Pages 1023-1036
Mots-Clés carrying-capacity; elliptical Fourier analysis; fish; holistic approach; identification; management; Mediterranean Sea; mitochondrial-dna; population structure; population-structure; spatial structure; stock mixture analysis; western atlantic
Résumé Two stocks of bluefin tuna (Thunnus thynnus) inhabit the north Atlantic; the western and eastern stocks spawn in the Gulf of Mexico and the Mediterranean Sea respectively. Trans-Atlantic movements occur outside spawning time whereas natal homing maintains stock structure. Commercial fisheries may exploit a mixed assemblage of both stocks. The incorporation of mixing rates into stock assessment is precluded by uncertainties surrounding stock discrimination. Otolith shape descriptors were used to characterise western and eastern stocks of Atlantic bluefin tuna in the present study and to estimate stock composition in catches of unknown origin. Otolith shape varied with length and between locations and years. Within a restricted size range (200-297-cm fork length (FL)) the two stocks were distinguished with an accuracy of 83%. Bayesian stock mixture analysis indicated that samples from the east Atlantic and Mediterranean were predominantly of eastern origin. The proportion assigned to the eastern stock showed slight spatial variation; however, overlapping 95% credible intervals indicated no significant difference (200-297 cm FL: central Atlantic, 73-100%; Straits of Gibraltar, 73-100%; Morocco, 50-99%; Portugal 64-100%). Otolith shape could be used in combination with other population markers to improve the accuracy of mixing rate estimates for Atlantic bluefin tuna.
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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 1323-1650 ISBN Médium
Région Expédition Conférence
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Numéro d'Appel MARBEC @ alain.herve @ collection 1681
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Auteur (up) Carpentier, A.S.; Berthe, C.; Ender, I.; Jaine, F.R.A.; Mourier, J.; Stevens, G.; De Rosemont, M.; Clua, E.
Titre Preliminary insights into the population characteristics and distribution of reef (Mobula alfredi) and oceanic (M. birostris) manta rays in French Polynesia Type Article scientifique
Année 2019 Publication Revue Abrégée Coral Reefs
Volume 38 Numéro 6 Pages 1197-1210
Mots-Clés aggregation; australia; bottle-nosed dolphins; california; Citizen science; conservation; Ecotourism management; habitat use; identification; marine park; movements; sharks; Site fidelity; Spatial connectivity; Sympatry
Résumé In French Polynesia, both currently recognized manta ray species, Mobula alfredi and M. birostris, are observed. Despite being an important cultural asset and generating significant economic benefits through manta ray watching tourism, published data on the ecology and threats to these species in the region are scarce. Based on an 18-year dataset of sighting records collected by citizen scientists and during two scientific expeditions, this study provides the first insights into the population characteristics and regional distribution of the two manta ray species in French Polynesia. A total of 1347 manta ray photographs (1337 for M. alfredi and 10 for M. birostris) were examined for the period January 2001-December 2017, with photo-identification techniques leading to the successful identification of 317 individual M. alfredi and 10 individual M. birostris throughout the Society, Tuamotu and Marquesas Islands. We provide the first confirmation of sympatric distribution of both species in the Society Islands. Our results highlight strong and long-term site fidelity of M. alfredi individuals to certain aggregation sites (> 9 years for 16 individuals) and reveal some degree of connectivity between populations, with 10 individuals recorded moving between islands located up to 50 km apart. Analysis of photographs of individuals bearing sub-lethal injuries (n = 68) suggests that M. alfredi are more likely to be injured at inhabited islands (Maupiti or Bora Bora; 75% of all injured individuals) than at uninhabited islands, with 75% of injuries related to boat propeller strikes and fishing gear entanglements. Our findings emphasize the need for further research to allow for a comprehensive evaluation of population structure, size and threats to manta rays in this region.
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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 0722-4028 ISBN Médium
Région Expédition Conférence
Notes WOS:000496024100010 Approuvé pas de
Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2658
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Auteur (up) Durand, J.-D.; Hubert, N.; Shen, K.-N.; Borsa, P.
Titre DNA barcoding grey mullets Type Article scientifique
Année 2017 Publication Revue Abrégée Rev. Fish. Biol. Fish.
Volume 27 Numéro 1 Pages 233-243
Mots-Clés coi; fish assemblages; genetics; identification; level; management; marine fishes; maximum-parsimony methods; mitochondrial phylogeny; Mugilidae; new-caledonia; south-america; species diversity; Taxonomy; teleostei mugilidae
Résumé Despite the ecological and commercial importance of grey mullets (fish family Mugilidae), their taxonomy and systematics are still much debated. Reasons for this are the low level of morphometric variability and the relatively poor phylogenetic information borne by the morpho-anatomical characters used thus far in diagnosing species. Here, we evaluate the potential of DNA barcoding to accurately delineate species and assign unknown specimens to taxa in the family Mugilidae. Our reference sample consists of 257 individuals from 91 lineages characterized by their nucleotide sequences at the COI, cytochrome b, and 16S rRNA loci. These lineages correspond to 55 species according to the current taxonomy, and 36 presumed cryptic species. All known and presumed cryptic species within the 'Mugil cephalus' (n = 15) and 'M. curema' (n = 6) species complexes, as well as within genera Chelon (n = 10), Crenimugil (n = 6), Osteomugil (n = 6), and Planiliza (n = 18) were successfully recovered as distinct lineages by COI gene sequences (598 bp), demonstrating the utility of this marker to delineate species in the family Mugilidae. Inconsistencies in the labeling of sequences deposited in GenBank were ascribed to species misidentification. A proportion of these misidentifications occurred in the course of dedicated barcoding surveys, further emphasizing the need for an accurate and exhaustive reference barcoding database for Mugilidae.
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Volume de collection Numéro de collection Edition
ISSN 0960-3166 ISBN Médium
Région Expédition Conférence
Notes Approuvé pas de
Numéro d'Appel MARBEC @ alain.herve @ collection 2109
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