Distribution and abundance of marine birds in the Eastern Indian Ocean

Abstract

A survey of pelagic seabird distribution in the eastern Indian Ocean was conducted during October 1987. Five seabird assemblages were identified, associated with different marine environments. Sea surface salinity appeared to be the most important factor in tropical, oceanic waters and sea surface temperature in shelf waters. A distinct and relatively species-rich community occurred over the South Equatorial Current, where seabird biomasses were relatively high, albeit patchily distributed. Overall, the patterns of abundance of pelagic seabirds north-west of Australia reflected the known patterns of nutrient enrichment and marine productivity. There was evidence of some biogeographic commonality in seabirds between the tropical Pacific and eastern Indian Oceans, resulting from a 'throughflow' of water types.