ES60 Water Column Sonar Data Collected During BE201201

A broad-scale, baseline acoustic-trawl surveys of pelagic fishes were conducted in late summer 2012 over the continental shelf of the ice-free U.S. northern Bering and Chukchi Seas on the F/V Bristol Explorer, a 55 m chartered fishing vessel. The goal of this work was to characterize the abundance and distribution of abundant pelagic fishes in the area to better understand the structure and function of these ecosystems. Fish species of interest included commercial subarctic species, which could expand northward in response to warming. The survey was conducted along 0.5 degree spaced transect lines from 59.75N to 73N between 170W and 157W. The primary water column acoustic instrument for the survey was a Simrad ES60 scientific echosounder equipped with a Simrad ES38-10 38 kHz transducer and ES120-7C 120 kHz transducer. The ship departed Dutch Harbor, AK on 01 August 2012, making intermediate port calls to Nome AK before ending in Dutch Harbor, AK on 29 September 2012. The echosounder was calibrated with a 38.1 mm tungsten-carbide sphere via the standard sphere method in Dutch Harbor, AK on 03 August 2012 and again at the end of the survey on 28 September 2012. The results of these surveys and further description of data collection are available in: De Robertis, A., Taylor, K., Wilson, C., and Farley, E. 2017. Abundance and Distribution of Arctic cod (Boreogadus saida) and other Pelagic Fishes over the U.S. Continental Shelf of the Northern Bering and Chukchi Seas Deep-Sea Research II, 135: 51-65. http://dx.doi.org/10.1016/j.dsr2.2016.03.002