Seasonal and interannual variability in the diet of young and subadult male Antarctic fur seals as revealed by stable C and N isotope ratios

Drago, Massimiliano; Llorach, Celia; Cruz, Unai Ormazabal Santa; Zenteno-Devaud, Lisette; Rebolledo Lorena; Rita, Diego; Gazo, Manel; Cardona, Luis

Abstract

Detailed knowledge of marine mammal diet is critical to understand their ecological roles and for the adequate manage-ment of marine resources. Antarctic fur seals (Arctocephalus gazella) in the Southern Atlantic Ocean rely largely on Antarctic krill (Euphausia superba) during the summer months, but their winter diet remains largely unknown. Here, stable carbon and nitrogen isotope ratios in whiskers and blood of young (2-3 years old) and subadult (4-7 years old) Antarctic fur seal males from the South Shetland Islands were used to assess the seasonal and interannual changes in the krill contribution to their diet. The stable isotope ratios revealed that krill dominated the diet of young and subadult male Antarctic fur seals year-round, with penguins, and not fish, as the second major prey, regardless of year and season. The year-round reliance of young and subadult male Antarctic fur seals on krill should be considered for ecosystem-based fisheries management, as they represent the bulk of the fur seal population remaining off Antarctica during the winter months.

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Título según WOS: ID WOS:000891773200001 Not found in local WOS DB
Título de la Revista: CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES
Volumen: 80
Número: 1
Editorial: Canadian Science Publishing
Fecha de publicación: 2023
Página de inicio: 69
Página final: 84
DOI:

10.1139/cjfas-2022-0145

Notas: ISI