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, NICOLAS E; DELLABIANCA NATALIA A.; RICCIALDELLI LUCIANA

POLAR BIOLOGY

SPRINGER

Lugar: Berlin; Año: 2021 vol. 44 p. 1655 - 1667

0722-4060

Cetaceans are known to play an important role in ecosystem structure anddynamics because they occupy the highest position in food webs. In order toimprove our knowledge on the feeding ecology of the long finned pilot whale, Globicephalamelas edwardii, in the western South Atlantic Ocean, we analyzed carbon (d13C) and nitrogen (d15N) stable isotopecomposition of bone collagen from 54 specimens found stranded along the coastof Tierra del Fuego, Argentina. Through Bayesian mixing models we estimated thecontribution of the most putative prey to the consumer´s diet. Prey specieswere selected, based on previous knowledge and covered all possible foragingareas for the region that were analyzed through a visual spatial analysis(based on sightings records). Based on ourresults, the long finned pilot whale is mainly a teutophagous species, feedingon squids, and can complement its diet with neritic prey when movingsporadically to coastal areas. We found that the southeastern part of Tierradel Fuego, north of Staten Island and the slope break around the Burdwood Bankare plausible feeding areas, which offer suitable habitats where pilot whalescan search for their preferred prey. These areas are important for Argentin´sconservation policies, since they enclose three oceanic Marine Protected Areas(Namuncurá-Burdwood Bank, BurdwoodBank II and Yaganes). Therefore, it is crucial to improve theknowledge regarding their foraging preferences in order to provide support forconservation and management strategies in these MPAs.