Bait defence behaviour of wolffish and its impact on long-line catch rates

Abstract

During an acoustic tagging experiment on cod in the Barents Sea in March 1995 a hierarchy among fish species was revealed, in which a wolffish (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 hooking rate for other species. If long-line catch data are used for stock assessment purposes, the presence of wolffish might reduce the catchability coefficient (q) of other species, in this case cod and haddock.