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Jaquemet, S; Potier, M; Cherel, Y; Kojadinovic, J; Bustamante, Paco; Richard, P; Catry, T; Ramos, J; Le Corre, M. |
Over 6-million pairs of sooty terns Sterna fuscata breed once a year in the southwest Indian Ocean, mostly on three islands of the Mozambique Channel (Europa, Juan de Nova and Glorieuses) and in the Seychelles region. Seasonal reproduction in either winter or summer is the dominant strategy in the area, but non-seasonal reproduction also occurred in some places like at Glorieuses Archipelago. The feeding ecology of the sooty tern was investigated during the breeding seasons to determine whether terns showed significant differences in their trophic ecology between locations. Regurgitations were analyzed to describe the diet of individuals when breeding, and stable isotopes and mercury concentrations were used to temporally integrate over the medium-term of... |
Tipo: Text |
Palavras-chave: Mercury δ 15N δ 13C fish larvae flying squid feeding ecology Seabirds. |
Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-4654.pdf |
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Cherel, Y; Le Corre, M; Jaquemet, S; Menard, Frederic; Richard, Pierre; Weimerskirch, H. |
Characteristics of the tropical oceanic environment (low productivity, little seasonality) and poor diversity of tropical seabird foraging methods and prey relative to temperate and polar species suggest that tropical seabirds overall encompass a narrow range of isotopic niches, with large overlaps among species. To test this hypothesis, we examined the stable carbon (delta C-13) and nitrogen (delta N-15) isotopic composition of blood and feathers of 5 seabird species from Europa Island, Mozambique Channel. While differences were small, blood delta C-13 and delta N-15 values characterized 5 distinct and non-overlapping trophic niches during the breeding period. Seabirds used 2 distinct foraging areas (delta C-13), one used by sooty tern Sterna fuscata and... |
Tipo: Text |
Palavras-chave: Trophic segregation; Tuna; Sooty tern; Pelagic ecosystem; Frigatebird; Booby. |
Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-4675.pdf |
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Cherel, Y; Ducatez, S; Fontaine, C; Richard, Patrice; Guinet, C. |
Trophic interactions between organisms are the main drivers of ecosystem dynamics, but scant dietary information is available for wide-ranging predators during migration. We investigated feeding habits of a key consumer of the Southern Ocean, the southern elephant seal Miroungia leonina, by comparing its blood delta(13) C and delta N-15 values with those of various marine organisms, including crustaceans, squid, fishes, seabirds and fur seals. At the end of winter, delta C-13 values (-23.1 to -20.1 parts per thousand)indicate that female elephant seals forage mainly in the vicinity of the Polar Front and in the Polar Frontal Zone. Trophic levels derived from delta N-15 values (trophic level = 4.6) show that the southern elephant seal is a top consumer in... |
Tipo: Text |
Palavras-chave: Squid; Southern Ocean; Pelagic ecosystem; Myctophid; Mesopelagic fish; Cephalopod. |
Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-5021.pdf |
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