Articolo in rivista, 2020, ENG, 10.1080/24750263.2020.1720832

The diet of Weddell seals (Leptonychotes weddellii) in Terra Nova Bay using stable isotope analysis

Rumolo, P.; Zappes, I. A.; Fabiani, A.; Barra, M.; Rakaj, A.; Palozzi, R.; Allegrucci, G.

Università degli Studi di Roma Tor Vergata; Consiglio Nazionale delle Ricerche

Stable isotope analyses were used to investigate the diet of Weddell seals in Terra Nova Bay (Ross Sea) and the potential variation of their foraging behaviour with age, sex and body mass. For this purpose, skin samples were collected from adult breeding seals and pups, together with muscle samples of their potential prey. Our results showed variation in foraging behavior between age classes, with pups reporting lower ?C values than adults, while no significant differences in ?N were recorded. In addition, contrary to expectations, a mixing model analysis showed that adult seals foraged mainly on shallow benthic prey, such as Trematomus spp. (34.1%) and Dissostichus mawsoni (21.1%), rather than on pelagic fish, such as Pleuragramma antarcticum (9.8%). Overall, with this paper we provide novel diet information on a seal colony not previously sampled, adding new insight into the feeding ecology of a top Antarctic predator.

The European Zoological Journal 87 (1), pp. 94–104

Keywords

Antarctica, Leptonychotes weddellii, stable isotopes, Terra Nova Bay, Weddell seal diet

CNR authors

Rumolo Paola, Barra Marco

CNR institutes