Patterns in the diet of mackerel icefish (Champsocephalus
gunnari) on the South Georgia and Shag Rocks shelf
(CCAMLR Subarea 48.3)

The diet of the mackerel icefish was investigated from stomach contents analysis of fish caught in research trawls at South Georgia and Shag Rocks in January 2004. The results are consistent with previous studies, with the dominant species consumed being Antarctic krill (Euphausia superba), the pelagic amphipod (Themisto gaudichaudi) and mysids. The diet differed between the age classes of icefish examined (2+, 3+ and 4++), with the younger fish consuming more T. gaudichaudi and small euphausids and the older fish taking more krill and fish. The change in diet reflects a shift from smaller to larger prey items with size.