Abundance and Distribution of Pilchard and Australian Anchovy as Prey Species for the Little Penguin Eudyptula minor at Phillip Island, Victoria

Abstract

The abundance of Pilchards Sardinops neopilchardus and Australian Anchovies Engraulis australis, the two main prey species of the Little Penguin Eudyptula minor at Phillip Island was estimated each month from mid-water and demersal trawl samples taken during the 1986-87 and 1987-88 Little Penguin breeding seasons. During the 1986-87 season, catch rates for Pilchard and Australian Anchovy were highest in October 1986 and next highest in February 1987. During the 1987-88 season, both were not caught until February 1988. The two species were widely distributed during October 1986 but were confined to a small area about 6 km south of the island during February 1987 and 1988. Sea surface temperatures were consistently higher during the second season when catch rates were lower. A total of 61 teleost and cephalopod species were caught during the study, but only four species were caught solely by midwater trawling. The decreased abundance of Pilchards and Australian Anchovies during the second season was reflected in the Little Penguin's diet, increased foraging range and reduced breeding success.