BASIS survey acoustics, 2008-2010 (B59)

The 2008-2010 Bering-Aleutian Salmon International Survey (BASIS) surveys were conducted on the Bering Sea shelf (~30 m to 500 m depth ranges) in August-October aboard the RV Oscar Dyson and FV Epic Explorer. Survey extent varied among the years. Acoustic data (Oscar Dyson - 18, 38, 70, 120, and 200 kHz; Epic Explorer - 38 kHz) were collected along transects between surface trawl stations. One or two midwater trawls were performed each day to identify targets observed on the acoustics. These data sets were analyzed using the 38 kHz acoustic data and midwater+surface trawl data for species or group assignment. Data are presented as integrated water column backscatter (i.e., acoustic energy summed within depth categories) within 0.5 nmi horizontal bins for species or scattering groups. Species or group assignment was made using surface and/or midwater trawl catch composition. Data are from both day and night periods. These data are considered to represent conservative backscatter estimates of age-0 pollock (Pollock0), age-1 pollock (Pollock1), capelin age-0+ (Capelin), Pacific herring (Herring), age-0 Pacific cod (PacificCod0), age-1+ Arctic cod (ArcticCod1+), age-1+ saffron cod (SaffronCod1+), rockfish/Atka mackeral/Pacific sandfish/sand lance/stickleback/rainbow smelt/prowfish (Other), and unidentified, non-partitioned species (UnkFish). Data were collected from 11 September 2008 through 04 October 2010.