The diet of itinerant male Hooker's sea lions, Phocarctos hookeri, at sub-Antarctic Macquarie Island

Scats were collected from itinerant male Hooker's sea lions, Phocarctos hoo keri, at Macquarie Island and the uneroded faunal remains used to assess th e diet. Uneroded sagittal otoliths were used to identify teleost fish and t o calculate fish size. Prey items included 14 taxa of teleost fish, cephalo pods, gastropods, crustaceans and fur seals. Fish constituted the primary c omponent of the diet. Prey species previously uncommon in the diet of seals and penguins around Macquarie Island were commonly eaten by Hooker's sea l ions. The sub-Antarctic horse fish (Zanclorhynchus spinifer) and the Patago nian tooth fish (Dissostichus eleginoides) were the two most abundant speci es and occurred in 62.5% and 41.7% of all scats respectively. There were no age-specific and individual differences in the diet of sea lions. Seasonal variances in diet were absent. Small plastic fragments (diameter similar t o 1 mm) were found only in association with otoliths of Electrona subaspera . Some overlap was seen between the diet of itinerant male Hooker's sea lio ns and the commercial fisheries that currently operate around Macquarie Isl and.