Development and Implementation of Trawl Sweep Modifications to Reduce Effects on Benthos and Commercially Valuable Crabs

A research collaboration between government scientists and the Bering Sea bottom trawl fleet identified gear modifications that reduced seafloor contact and effects on benthos and crabs. Elevating the cables (sweeps) connecting the trawl doors to the net a short distance (7.5 – 10 cm) maintained flatfish capture rates while providing space for non-target animals to pass under. As this fishery uses very long sweeps (up to 400 m) to herd flatfish into the trawl net, these modifications affect up to 90% of the area from which flatfish are captured during trawling. Requirements for this modification during all flatfish trawling in the Bering Sea were approved by the North Pacific Fisheries Management Council, with implementation beginning in January of 2011. Effective implementation was enhanced by active participation of fishery participants in initial development, testing, concept improvement, development and evaluation of regulations, discussions regarding practical enforcement and other troubleshooting.