| 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 in the Shelikof Strait, Marmot Bay,
and Chirikof shelf break areas of the Gulf of Alaska (GOA) during late winter/early
spring of 2015 to estimate the distribution and abundance of walleye pollock (Gadus
chalcogrammus). The survey was conducted 15-31 March (Marmot Bay, 15-16 March; Shelikof
Strait 17-23 March; Chirikof shelf break, 23-24 March), starting and ending in Kodiak,
Alaska. The survey was conducted aboard NOAA Ship Oscar Dyson, a 64 meter stern trawler
equipped with acoustic and oceanographic instrumentation. The primary instrument for
the survey was a Simrad EK60 split-beam echosounder system utilizing five frequencies
(18, 38, 70, 120, and 200 kHz). |