| Gulf of Alaska Acoustic-Trawl Survey of Walleye Pollock (DY1401, EK60). The Midwater
Assessment and Conservation Engineering (MACE) program of NOAA National Marine Fisheries
Service (NMFS), Alaska Fisheries Science Center (AFSC) conducted an acoustic-trawl
(AT) stock assessment survey in the Shumagin Islands and Sanak Trough areas of the
Gulf of Alaska (GOA) during the winter of 2014 to estimate the distribution and abundance
of walleye pollock (Gadus chalcogrammus). The survey was conducted 21-28 February
(Shumagin Islands 23-27 February; Sanak Trough 26 February), starting and ending in
Kodiak, Alaska. The survey was conducted aboard NOAA Ship Oscar Dyson, a 64 meter
stern trawler equipped with acoustic and oceanographic instrumentation. The primary
instrument for the survey was a Simrad EK60 split-beam echosounder system utilizing
five frequencies (18, 38, 70, 120, and 200 kHz). |