The only interaction observed between longliners fishing for Patagonian toothfish (Dissostichus eleginoides) to the west of the Kerguelen Islands during the 1995/96 cruise and marine mammals occurred with the Antarctic fur seal (Arctocephalus gazella). These seals are responsible for the loss of 0.75 % of toothfish during the longline sets in which interaction occurred, as against 2.2 % of fish lost from the hooks during line hauling.