Seabird by-catch and bait loss in long-lining using different setting methods

Abstract

Seabirds taking baits during long-line setting occasionally become caught and are killed, while the associated bait loss may have serious impact on long-lining efficiency and profitability. Two different setting methods were tested as a solution to this problem in the autoline fishery in the north Atlantic; lines were set either through a setting funnel that guided the baited line beneath the sea surface or a seabird scaring device was used. Bait loss and the catches of target species and seabirds were compared with and without such methods. Accidental catches of birds were reduced by both methods, most effectively by the seabird scarer. Losses of mackerel bait were also significantly reduced by using the scarer, but not by using the setting funnel. No increase in the catches of target species was demonstrated by using either of the setting methods. However, bait loss caused by seabirds was regarded as a minor problem in this fishing experiment. Suggestions on how to improve the efficiency of the two methods tested are discussed, and a combination of these methods is proposed as a method to reduce greatly the incidental capture of seabirds in the autoline fishery in the north Atlantic.