EK60 Water Column Sonar Data Collected During OD0707

AFSC Echo Integration-Trawl of Walleye Pollock (Theraga chalcogramma) on the U.S. and Russian Bering Sea Shelf in June and July 2007 (OD0707, 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 survey of abundance and distribution of walleye pollock (Theragra chalcogramma; Gadus chalcogramma) on the U.S eastern Bering Sea shelf and Russian Cape Navarin areas 2 June to 30 July 2007. The survey was conducted aboard NOAA Ship Oscar Dyson, a 64 meter stern trawler equipped with acoustic and oceanographic instrumentation, utilizing a Simrad EK60 split-beam echosounder system equipped with five frequencies (18, 38, 70, 120, and 200 kHz). The survey was conducted in three legs starting and ending in Dutch Harbor, Alaska with all port calls in Dutch Harbor. Leg 1 was conducted 2-20 June, leg 2 was conducted 21 June to 9 July, and leg 3 was conducted 11-30 July. Standard acoustic system sphere calibrations were conducted at the start of the cruise (2 June), at the start of leg 2 (21 June), at the end of leg 2 (8 July), and at the end of the cruise (29 July); all calibrations were accomplished in Captains Bay, Dutch Harbor.