| Gulf of Alaska Acoustic-Trawl Survey of Walleye Pollock (DY1506, 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 in the Gulf of Alaska (GOA) during late spring and summer
of 2015 to estimate the distribution and abundance of walleye pollock (Gadus chalcogrammus).
The survey area included the GOA shelf from the Islands of Four Mountains to Chiniak
Trough including many associated bays and troughs. The survey was conducted from June
11 to August 16, 2015 in three legs, starting and ending in Kodiak, Alaska, with intermediate
port calls in Kodiak, Alaska. The survey was conducted aboard NOAA Ship Oscar Dyson,
a 64 meter stern trawler equipped with acoustic and oceanographic instrumentation,
and biological sampling capabilities. The primary instrumentation for the survey was
a Simrad EK60 split-beam echosounder system utilizing five frequencies (18, 38, 70,
120, and 200 kHz) and a Simrad ME70 multibeam echosounder, with the ME70 trigger synchronized
to the EK60 system. |