Environmental determinants of top predator distribution within the dynamic winter pack ice zone of the northern Antarctic Peninsula

摘要: Global warming is predicted to reduce the amount of sea ice concentration in polar environments, thus presenting profound changes for populations seabirds and marine mammals dependent on ice. Using data from a shipboard survey during August 2012, I test hypothesis that relative abundance seabird reflects environmental variability associated with dynamic pack zone. observations concentration, quantified an gradient describes spatial organization The relationship top predators this revealed three important aspects: (1) open water community present some predator species exhibiting higher moderate (40–60 %) as opposed edge (10 %), (2) Antarctic fur seals (Arctocephalus gazella) were most abundant pinniped they observed resting floes foraging within leads polynyas, (3) species, regression models indicate latitude (a principal north/south gradient) are determinants. Winter ocean conditions may strongly influence population dynamics predators; therefore, information regarding their habitat use winter needed understanding ecosystem dynamics.