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| Le Croizier, Gaël; Lorrain, Anne; Sonke, Jeroen E.; Jaquemet, Sébastien; Schaal, Gauthier; Renedo, Marina; Besnard, Lucien; Cherel, Yves; Point, David. |
| In coastal ecosystems, top predators are exposed to a wide variety of nutrient and contaminant sources due to the diversity of trophic webs within coastal areas. Mercury contamination could represent an additional threat to shark populations that are declining worldwide. Here we measured total mercury, carbon and nitrogen isotopes as well as mercury isotopes in two co-occurring shark species (the bull shark Carcharhinus leucas and the tiger shark Galeocerdo cuvier) and their prey from a coastal ecosystem of the western Indian Ocean (La Réunion Island), to (i) determine their main trophic Hg source and (ii) better characterize their diet composition and foraging habitat. Hg isotope signatures (Δ199Hg and δ202Hg) of shark prey suggested that bull sharks were... |
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| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00633/74465/74289.pdf |
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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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