EK60 Water Column Sonar Data Collected During DY1207

Acoustic-Trawl Survey of Walleye Pollock on the U.S. and Russian Bering Sea Shelf (DY1207, 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 on the U.S. and Russian Bering Sea shelf during late spring/summer of 2012 to estimate the distribution and abundance of walleye pollock (Theraga chalcogramma). The survey was conducted from Bristol Bay, eastern Bering Sea in the U.S. to Cape Navarin, Russia, 7 June to 10 August aboard NOAA Ship Oscar Dyson, a 64 meter stern trawler equipped with acoustic and oceanographic instrumentation. The vessel departed Dutch Harbor, Alaska on 7 June and returned to Dutch Harbor on 10 August. The cruise was completed in three legs (leg 1, 7-25 June; leg 2, 30 June to 18 July; leg 3, 23 July to 10 August), with all port calls in Dutch Harbor, Alaska. The EK60 echosounder system was calibrated prior to and at the end of the cruise in Captains Bay, Dutch Harbor, Alaska.