NPRB 1117 Cooperative research to develop new trawl footrope designs to reduce mortality of southern Tanner and snow crabs (Chionoecetes bairdi and C. opilio) incidental to Bering Sea bottom trawl fisheries

Alaska’s Bering Sea is home to some of the world’s most productive groundfish and crab stocks and the fisheries that depend on them. Their spatial overlap creates problems when bottom trawls affect crabs in their paths, either through capture and discard or damage to crabs that remain on the seafloor. We worked with Bering Sea bottom trawlers to develop and test changes to trawl footropes to minimize crab mortality, by reducing damage to crabs that are not caught, and maintaining low crab capture rates. A previous NPRB project (0711) showed that crab mortality from herding cables ahead of trawls could be greatly reduced with simple modifications to raise them above the seafloor. This project did the same for trawl footropes, the part of the trawl located between the leading edge of the trawl net and the seafloor. Such gear changes allow crab mortality to be reduced without restricting trawling to the few areas of the Bering Sea without crabs.