Antarctic seabirds and marine mammals related to krill biomass Euphausia superba, Bransfield Strait and Elephant Island

Abstract

During the XVI Peruvian Antarctic Expedition on summer of 2006 seabirds and marine mammals observations were conducted at the Bransfield Strait and around the Piloto Pardo Islands. 17 species of seabirds and 7 species of marine mammals were identified. The Sampling Basic Unit (SBU) was 0.25 nm, having at the end of the track, a number of 636 SBU. Seabirds and marine mammals’ observations were analyzed in relation to the presence and biomass of its main prey, krill (Euphausia superba). Seven species of seabirds and two species of mammals showed a significant association between its presence and krill. There were found highly significant differences in the seabirds abundance mean between the SBU’s that presented krill and the SBU that did not present it. On the other side, when comparing krill’s biomass mean per SBU with seabirds no difference was found. Results indicate that the Pygoscelis antarctica, Fulmarus glacialoides and Spheniscidae family could be considered good indicators of the presence of krill. Due to the few marine mammals observations conducted during the expedition, no significate differences were found.