Feeding ecology of the long finned pilot whale, Globicephala melas edwardii, in the southwestern Atlantic Ocean, determined by stable isotopes analysis

BECKER YAMILA A.; FIORAMONTI NICOLÁS E.; DELLABIANCA NATALIA A.; RICCIALDELLI LUCIANA

POLAR BIOLOGY

SPRINGER

Lugar: Berlin; Año: 2021

0722-4060

Cetaceans are known to play important roles in the structure and dynamics of the ecosystems because they occupy the highest positions in food webs. In order to improve our knowledge on the feeding ecology of the long-finned pilot whale, Globicelphala melas edwardii, at the western South Atlantic Ocean, we analyzed carbon (13C) and nitrogen (15N) stable isotope composition of bone collagen from 54 specimens found stranded along the coast of Tierra del Fuego, Argentina. Through Bayesian mixing models we estimated the contribution of the most putative prey to the consumer diet. Prey species were selected based on previous knowledge and from restricted foraging areas that were constrained through a visual spatial analysis (based on sightings records). Based on our results, long finned pilot whale is mainly a teutophagous species, feeding on squids, and can complement its diet with neritic prey when moving sporadically to coastal areas. We found that the southeastern part of Tierra del Fuego, north of the Staten Island and the slope break around the Burdwood Bank are plausible feeding areas, which offer suitable habitats where pilot whales can search for their preferred prey. These areas are important for Argentina conservation priorities, since they host three oceanic Marine Protected Areas (Namuncurá-Burdwood Bank, Burdwood Bank II and Yaganes). Therefore, it is crucial to improve the knowledge regarding their foraging preferences in order to provide support for conservation and management strategies in these MPAs.