AFSC/RACE/GAP/McConnaughey: Trawlex BACI

The Resource Assessment and Conservation Engineering (RACE) Division of the Alaska Fisheries Science Center (AFSC) conducted a survey in the eastern Bering Sea (EBS) to evaluate short-term impacts of bottom trawls on soft-bottom benthic habitats and to describe the recovery process. This was a multi-year project which follows earlier studies of long-term bottom trawling impacts in the same general region. The study area was within the Crab and Halibut Protection Zone 1 in Bristol Bay (management area 512; approximately latitude 58 degrees north and longitude 160 degrees west. In general, at-sea work was divided into three phases: (1) integrated biological and geological sampling before experimental trawling, (2) experimental trawling and (3) integrated biological and geological sampling after experimental trawling. Survey activities were conducted aboard the 47.2 meter (155 ft) chartered vessel Ocean Explorer. This was a commercial fishing vessel modified to support the research activities. Activity during phase 1 consisted of side scan assessments of seafloor morphology with an interferometric Klein 5410 side scan sonar towfish during night wheel watches, and epifauna trawls and collection of infauna and sediment grabs during daylight hours. All samples from a particular gear were collected in succession, so as to minimize time spent installing and configuring gear during phases (1) and (3). Assessment activities after the impact phase were a repeat of activities prior to experimental trawling.