A comparison of ocean fronts and seabird occurrence in the GLOBEC study area, and the greater Southern Ocean

D. Ainley, C. Ribic, C. Tynan, E. Chapman, K. Dugger, G. Ford, W. Fraser, B. Raymond, and E. Woehler

We investigated the importance of the major ocean fronts to defining biotic regimes in the Southern Ocean in order to better understand the role of highly compacted fronts in affecting faunal boundaries in waters off the western Antarctic Peninsula. Included are the Antarctic Polar Front, the southern boundary of the Antarctic Circumpolar Current, the Antarctic Slope Front, and the large-scale pack ice edge. To conduct this assessment, we used seabirds, which have the mobility to occur over very broad regions but which, on the basis of past, regional research, do exhibit definite faunal boundaries. Data were compiled from ~40 cruises conducted since the late 1970s to the present, and spanning the Southern Ocean from about 50S to the continent and around most of its circumference. Cruises were separated temporally on the basis of season: summer vs. winter.