Contribution of fishery discards to the diet of the Black-browed albatross (Thalassarche melanophris) during the non-breeding season: an assessment through stable isotope analysis

ROCIO MARIANO-JELICICH; SOFIA COPELLO; JUAN PABLO SECO PON; MARCO FAVERO

MARINE BIOLOGY

SPRINGER

Lugar: Berlin; Año: 2014 vol. 161 p. 119 - 129

0025-3162

Abstract  Black-browed albatrosses (Thalassarche melanophris) disperse over the argentinean Continental Shelf and neighboring waters during their non-breeding season. It is one of the most frequent seabirds attending fishing vessels and also the most common Procellariform in the bycatch of longliners and trawlers in the area. Understanding the use of ishery discards by this species is an important issue when assessing the potential effect of strategic discard management in decreasing the abundance, interactions, and mitigating mortality. In the present study, we analyzed carbon and nitrogen stable isotope compositions in the blood of Black-browed albatrosses to assess the relative contribution of discards from different isheries to the diet of this species in winter. Samples were obtained in winter 2011 from ishing vessels operating between 41°43´S and 57°59´W.  No sex differences in  δ13C and δ15 N were observed. results indicate that during their non-breeding season, isotopic signatures of Black-browed albatrosses are closer to discards and offal generated by fisheries and in particular by trawlers. The large ishing effort of trawl isheries in argentina highlights the urgency of an exhaustive analysis to find practical and effective ways to reduce the number of seabirds attending trawlers.