EK60 Water Column Sonar Data Collected During DY1303

Gulf of Alaska Acoustic-Trawl Survey of Walleye Pollock (DY1303, 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 late winter/early spring of 2013 to estimate the distribution and abundance of walleye pollock (Gadus chalcogrammus). The vessel departed Kodiak, Alaska on 14 March arriving at the start of the first survey on 15 March. The Marmot Bay survey was conducted 15-16 March, Shelikof Strait 16-25 March, and Gulf of Alaska shelf break east of Chirikof Island 25-27 March. The vessel arrived in Kodiak 28 March following a post-cruise EK60 calibration on 27 March in Three Saints Bay, Kodiak Island, Alaska. The survey was conducted aboard NOAA Ship Oscar Dyson, a 64 meter stern trawler equipped with acoustic and oceanographic instrumentation.