The physical and biological features affecting to top predator assemblages in Antarctica

Ari Friedlaender, Patrick Halpin, Daniel Costa, William Fraser, and others.

Predators are not randomly distributed throughout available habitat, but instead select areas based on some combination of physical and biological factors. During SO GLOBEC, measurements were made across a range of top predators in an effort to describe specific distribution patterns in relation to physical oceanographic processes and the distribution and behavior of their main prey, krill. Our analysis will 1) determine how habitat utilization varies across and between predator species, 2) locate biological hot spots or areas of common species assemblages, and 3) determine the physical and biological characteristics shared by these areas. Understanding the similarities and differences in how predator groups are distributed, will allow for more refined and detailed examination of the foraging behavior of predators with respect to their horizontal, vertical, and temporal habitat use patterns to determine niche separation and the potential for competitive interactions. Furthermore, this research will facilitate more quantitative analyses of the energetic requirements of predator groups and how the effects of changing climate and prey availability.