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

MARIANO Y JELICICH, ROCÍO; COPELLO, SOFIA; SECO PON, JUAN PABLO; FAVERO, MARCO

MARINE BIOLOGY

SPRINGER

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

0025-3162

Black-browed albatrosses (Thalassarche melanophris)disperse over the Argentinean Continental Shelfand neighboring waters during their non-breeding season.It is one of the most frequent seabirds attending fishingvessels and also the most common Procellariform in thebycatch of longliners and trawlers in the area. Understandingthe use of fishery discards by this species is an importantissue when assessing the potential effect of strategicdiscard management in decreasing the abundance, interactions,and mitigating mortality. In the present study, weanalyzed carbon and nitrogen stable isotope compositionsin the blood of Black-browed albatrosses to assess therelative contribution of discards from different fisheries tothe diet of this species in winter. Samples were obtainedin winter 2011 from fishing vessels operating between41–43°S and 57–59°W. No sex differences in δ13C andδ15N were observed. Results indicate that during their nonbreedingseason, isotopic signatures of Black-browed albatrossesare closer to discards and offal generated by fisheriesand in particular by trawlers. The large fishing effortof trawl fisheries in Argentina highlights the urgency of anexhaustive analysis to find practical and effective ways toreduce the number of seabirds attending trawlers.