EK60 Water Column Sonar Data Collected During DY1001

Gulf of Alaska Acoustic-Trawl Surveys of Walleye Pollock (DY1001, EK60). The Midwater Assessment and Conservation Engineering (MACE) program of NOAA National Marine Fisheries Service (NMFS), Alaska Fisheries Science Center (AFSC) conducted acoustic-trawl (AT) stock assessment surveys in the Gulf of Alaska (GOA) during the winter of 2010 to estimate the distribution and abundance of walleye pollock (Theragra chalcogramma). The vessel departed Kodiak, Alaska on 22 February and conducted an EK60 echosounder system calibration in Three Saints Bay, Kodiak Island, Alaska. The vessel conducted the Shumagin Islands survey (including Shumagin Trough, Stepovak Bay, Renshaw Point, Unga Strait, and West Nagai Strait) 23-25 February. The vessel then surveyed Sanak Trough, Marzhovoi Bay, and Pavlof Bay, 26-28 February, followed by fisheries research work on Snakehead shelf, 1-2 March. Acoustic-trawl surveys were conducted in Kenai Peninsula Bays (2-5 March), Prince William Sound (5-7 March), and Marmot Bay (8-9 March) with the survey ending in Kodiak, Alaska on 9 March, 2010. The survey was conducted aboard NOAA Ship Oscar Dyson, a 64 meter stern trawler equipped with acoustic and oceanographic instrumentation.