An attempt to improve size selection in pelagic longline fisheries for haddock

Bycatches of haddock (Melanogrammus aeglefinus) below legal size (44 cm tot al length) in the pelagic longline fisheries off the coast of Finnmark, nor thern Norway, are often high. To reduce the bycatch of undersized haddock, we conducted experiments involving modifications in gear technology and fis hing strategy. We tested longlines with a greater rate of sinking, hooks wi th an inedible plastic body attached to the shank, hooks with nylon bristle s attached to the shank, restructured bait based on mackerel (Scomber scomb rus) and sandeel (Ammodytes lancea), mackerel bait of twice the normal size and restructured mackerel bait of twice the normal size. The inedible plastic body reduced the catch of undersized haddock, as well as the total catch. Restructured sandeel bait gave a significant decrease i n catches of undersized haddock, but the number of hooks deployed in this p art of the experiment was small. Traditional mackerel bait of twice the nor mal size resulted in about a 40% reduction in the catch of undersized fish. Catch proportions between length groups in the alternative gears compared to control gear or length distribution based on acoustical data indicate a unimodal selection curve for the alternative gears. (C) 2000 Elsevier Scien ce B.V. All rights reserved.