Some Approaches to Reducing Non-commercial Bycatch of Bottom Trawl Fisheries in the Western Bering Sea

This paper reports on a study of trawl bycatch in the western Bering Sea based on catch data obtained from nine bottom trawl surveys (a total 365 bottom trawl stations) and commercial fishing operations (a total 980 bottom trawl hauls) between 1995 and 1998. Minimum catch rates of non-commercial bycatch were registered west of 170°E and east of 180°while maximum catch rates were observed between 171-172°E, 173-175°E and 177-178°E. Minimum bycatch rates were observed at depths of less than 150 m while the proportion of non-commercial bycatch increased with depth and reached its maximum value at depths over 650 m. The maximum bycatch rates were observed in May and November and minimums were observed in December. The maximum bycatch rates were registered from 13:00 to 18:00. Minimum proportions of bycatch occurred between 19:00 and 24:00. Among the bycatch species, grenadiers may be used for canned liver and eggs and their flesh may be processed to human or animal food and probably to surimi. Skate wings are suitable for human consumption. Sculpins and eelpouts are suitable for processing to canned fish or human food. The remainder of the non-commercial bycatch species except for snailfishes may be processed to fish powder.