BAIT DEFENSE BEHAVIOR OF WOLFFISH AND ITS IMPACT ON LONG-LINE CATCH RATES

During an acoustic tagging experiment on cod in the Barents Sea in Mar ch 1995 a hierarchy among fish species was revealed, in which a wolffi sh (Anarhichas sp.) was observed to be dominant in relation to cod and haddock. When wolffish are present in the odour field of a bait, the aggressive bait-defence behaviour of this species might reduce the hoo king rate for other species. If long-line catch data are used for stoc k assessment purposes, the presence of wolffish might reduce the catch ability coefficient (q) of other species, in this case cod and haddock . (C) 1997 International Council for the Exploration of the Sea.