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Registros recuperados: 22 | |
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Le Croizier, Gaël; Lorrain, Anne; Schaal, Gauthier; Ketchum, James; Hoyos-padilla, Mauricio; Besnard, Lucien; Munaron, Jean-marie; Le Loch, Francois; Point, David. |
Worldwide shark populations have experienced rapid declines over the last decades, mainly due to overfishing. Marine protected areas (MPAs) have thus become an indispensable tool for the protection of these marine predators. Two recently-created MPAs in the Northeast Pacific Ocean, the Revillagigedo National Park and Clipperton atoll, are characterized by different trophic structures potentially influencing trophic niche and contaminant exposure for resident sharks in these two sites. In this context, we used carbon (δ13C) and nitrogen (δ15N) stable isotope analyzes as well as total mercury concentrations ([THg]) to assess the role of foraging site on the trophic niche and Hg levels of juvenile ST sharks Carcharhinus albimarginatus. Analyzing fin clip... |
Tipo: Text |
Palavras-chave: Top-predators; Mercury transfer; Food webs; Foraging habitat; Stable isotopes; MPAs. |
Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00619/73114/72257.pdf |
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Chauvaud, Laurent; Lorrain, Anne; Dunbar, Robert; Paulet, Yves; Thouzeau, Gérard; Jean, Frédéric; Guarini, Jean-marc; Mucciarone, David. |
We investigate the environmental and biological controls on oxygen isotope ratios in the shells of modern Pecten maximus bivalves collected alive in the Bay of Brest (France). Seasonal delta(18)O profiles, obtained by drilling the daily calcite ridges deposited at the surface of the left valve, were compared with in situ measurements of temperature and salinity. We show that P. maximus delta(18)O values accurately track seasonal variations in bottom water temperature. Shell growth rate has no significant effect on shell delta(18)O values. Our study demonstrates that daily variations in water temperature can be reconstructed within about 0.5 degrees C. Temperatures estimated with the paleotemperature equation established in this study were compared with... |
Tipo: Text |
Palavras-chave: Pecten Maximus; Brittany; Paleoenvironment; Estimation; Daily varition; Water temperature; Isotope; Calcite; Shell; Ëecten maximus; Paleotempérature; Variation saisonnière; Température eau; Strie croissance; Isotope; Coquille. |
Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/publication-643.pdf |
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Registros recuperados: 22 | |
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