Cetacean distribution off Eastern Antarctica (80-150 degrees E) during theAustral summer of 1995/1996

A line-transect marine science survey of the waters off East Antarctica (80 -150 degrees E; CCAMLR Division 58.4.1; IWC Areas IV and V) was conducted d uring the Austral summer of 1995/1996. A total of 350 h search effort resul ted in 342 sightings (746 animals) of 12 identified species and eight categ ories of unidentified cetaceans. Humpback whales (Megaptera novaeangliae) w ere the most frequently sighted species in terms of number of schools and n umber of individuals (82 sightings:159 animals). All humpback sightings wer e west of 120 degrees E; distributed over a wide latitudinal band from the ice edge out to the northern limit of the survey (63 degrees S); correlated with high integrated-Chi at > 50 mu m/m(2)); and generally concentrated in the waters to the south of the Antarctic Divergence and the Southern Bound ary of the Antarctic Circumpolar Current (ACC). Baleen whale distribution r eflected the overall patterns of biological productivity and oceanographic processes. Most animals were found to the west of 120 degrees E and to the south of the Southern Boundary of the ACC (which lies well offshore in this region) and the Antarctic Divergence, which coincided with the ACC between 85 and 135 degrees E on this survey. The large-scale patterns observed in this survey indicate that baleen whale species in the Southern Ocean may be concentrated in areas where extensive winter sea-ice cover and oceanograph ic features allow extended residence time in surface waters for primary pro ducers during the Austral summer ice retreat. Odontocete species were less abundant and generally concentrated at meso-scale high-productivity areas p roduced by the interactions of identifiable physical features, (C) 2000 Els evier Science Ltd. All rights reserved.