EK500 Water Column Sonar Data Collected During MF0309

Acoustic-Trawl Survey of Walleye Pollock in the Gulf of Alaska (MF0309, EK500). 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 Gulf of Alaska during late spring/early summer of 2003 to estimate the distribution and abundance of walleye pollock (Theragra chalcogramma). The survey was conducted along the Gulf of Alaska (GOA) shelf and shelfbreak from the Shumagin Islands to Prince William Sound, 4 June to 16 July 2003, aboard NOAA Ship Miller Freeman, a 66 meter stern trawler equipped with acoustic and oceanographic instrumentation. The vessel departed Kodiak, Alaska on 4 June and arrived in Kodiak on 16 July. The echosounder system was calibrated at the start of the cruise in Three Saints Bay, Kodiak Island, Alaska on 5 June, and at the end of the cruise in Ugak Bay, Kodiak Island, Alaska, 16 July 2003.