ME70 Water Column Sonar Data Collected During DY0909

Acoustic-Trawl Survey of Walleye Pollock on the U.S. and Russian Bering Sea Shelf (DY0909, ME70). 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 2009 to estimate the distribution and abundance of walleye pollock (Theragra chalcogramma). The survey was conducted from Bristol Bay, eastern Bering Sea in the U.S. to Cape Navarin, Russia, 9 June to 7 August aboard NOAA Ship Oscar Dyson, a 64 meter stern trawler equipped with acoustic and oceanographic instrumentation. The vessel departed Kodiak, Alaska on 5 June and arrived in Dutch Harbor, Alaska on 7 August. The cruise was completed in three legs (leg 1, 9-28 June; leg 2, 1-18 July; leg 3, 21 July to 7 August), with port calls in Dutch Harbor, Alaska; a personnel exchange occurred in Dutch Harbor on 21 June. Fisheries gear research operations were conducted on 16 June and again on 3-5 August. The Simrad EK60 and ME70 echosounder systems were calibrated at the start of the cruise in Three Saints Bay, Kodiak Island, Alaska 10-11 June, and the EK60 was calibrated at the end of the cruise in Anderson Bay, Unalaska Island, Alaska 6-7 August.