Antarctic marine birds and mammals related krill Euphausia superba in Bransfield Strait and Elephant Island

Abstract

We describe the distribution and diversity of Antarctic marine mammals and seabirds based on the observations made during the XVII Peruvian Expedition to the Antarctica (ANTAR XVII). The observations were made aboard the BIC Humboldt from 17th to 23rd January 2007. The observation effort was 718 and 470 nm for birds and mammals, respectively; from a total distance of 1078 nm. We analyzes the relationship between the composition and abundance of species and the spatial units of observation (transects) defined from the total track. A total of 16 species of seabirds and 5 of marine mammals were observed. The most abundant bird species were: Pygoscelis antartica, Fulmarus glacialoides, Daption capensis and Oceanites oceanicus, and for mammals: Megaptera novaeangliae and Orcinus orca. The niche breadth indices let us describe two groups in the species and families distribution: those associated with inshore (narrow niche) and those associated with both inshore and offshore (broad niche). Hierarchical clustering analysis of the units (transects) defined mainly two types of areas, characterized by their association to the coastline; and the species diversity indices identified significant spatial units both associated and non-associated to coast.