미국
AFSC/RACE/MACE: Results of 2014 Acoustic-trawl survey of the Shumagin Islands and Sanak Trough dy1401
The surveyâs primary objective was to collect acoustic data and trawl information to estimate midwater abundance and distribution of walleye pollock (Gadus chalcogrammus) in the Gulf of Alaska (GOA) Shumagins Region during late winter and early spring. Acoustic data were collected using five split-beam transducers (18, 38, 70, 120, and 200 kHz) and Simrad ER60 scientific echo sounders. Midwater and near-bottom acoustic backscatter was sampled using an Aleutian Wing 30/26 Trawl (AWT) and a poly Norâeastern bottom trawl (PNE) with roller gear. This long-running survey has consistently provided data on the pollock population in the western GOA during winter and spring months.