| Acoustic-trawl (AT) survey of Walleye Pollock in the Gulf of Alaska (DY1502, 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 (AT) stock assessment survey in the Shumagin Islands, Sanak Trough,
and Kenai peninsula bays in the Gulf of Alaska (GOA) during winter of 2015 to estimate
the distribution and abundance of walleye pollock (Gadus chalcogrammus). The survey
was conducted 10 February to 2 March with the vessel departing and returning to Kodiak,
Alaska (an intermediate port call in Kodiak, 14-18 February, was required due to a
vessel mechanical issue). The Shumagin Islands survey was conducted 13 February and
20-24 February, the Sanak Trough survey was conducted 22-23 February, and the Shumagin
Trough survey was conducted 23-24 February. The Shumagin Islands survey included Stepovak
Bay, Unga Strait, and West Nagai Strait. The Kenai peninsula bays survey was conducted
27 February to 1 March and included Resurrection Bay, Day Harbor, Port Bainbridge,
Ailik Bay, Harris Bay, Nuka Bay, Nuka Passage, and Port Dick. 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). |