The foraging range of Adelie penguins at Bechervaise Island, Mac. Robertson Land, Antarctica, and its overlap with the krill fishery

The foraging ranges of six female and four male Adélie penguins breeding at Bechervaise Island near Mawson Station (Mac. Robertson Land) were determined by satellite tracking, using the ARGOS system. Birds were tracked over four foraging trips (by 2 females and 4 males) during the incubation period (November-December 1991) and 17 trips (by 4 females and 2 males) throughout January 1992 when birds were feeding chicks. Most birds made foraging trips to the continental shelf break (1000m isobath) approximately 110 km distant at its closest point. Birds feeding chicks also made journeys of 1-2 days ranging up to 12 km after 17 January when the sea became ice free to the coast. Concentrations of krill Euphausia superba which have in the past been the subject of a fishery occur along the shelf break zone where the birds were foraging. There is potential therefore for overlap between the foraging range of Adélie penguins breeding along the Mac. Robertson Land Coast (approximately 150000 pairs) and any future harvest of krill in the region. The foraging range of the birds at Bechervaise Island considerably exceeds the 15-50 km determined for birds in the South Shetland and South Orkney Islands and reflects the distance offshore of krill one of their major food sources.