Gulf of Alaska Acoustic-Trawl Surveys of Walleye Pollock (DY1201, EK60). The Midwater Assessment and Conservation Engineering (MACE) program of NOAA National Marine Fisheries Service (NMFS), Alaska Fisheries Science Center (AFSC) conducted acoustic-trawl (AT) stock assessment surveys in the Gulf of Alaska (GOA) during the winter of 2012 to estimate the distribution and abundance of walleye pollock (Theraga chalcogramma). The vessel departed Kodiak, Alaska on 13 February, conducted EK60 echosounder system calibration on 14 February, then proceeded to the start of the first survey (Sanak Trough, 15 February). The vessel then proceeded to the Shumagin Islands and conducted surveys at Shumagin Trough, Stepovak Bay, Renshaw Point, Unga Strait, and West Nagai Strait, 16-19 February. The vessel conducted multibeam echosounder surveys of select locations and deployed ARGO drifters 19-22 February and returned to Kodiak on 22 February. The survey was conducted aboard NOAA Ship Oscar Dyson, a 64 meter stern trawler equipped with acoustic and oceanographic instrumentation.

Gulf of Alaska Acoustic-Trawl Survey of Walleye Pollock (DY1103, EK60). The Midwater Assessment and Conservation Engineering (MACE) program of NOAA National Marine Fisheries Service (NMFS), Alaska Fisheries Science Center (AFSC) conducted acoustic-trawl (AT) stock assessment surveys during the late spring/summer of 2011 in the Gulf of Alaska to estimate the distribution and abundance of walleye pollock (Theragra chalcogramma). The survey was conducted on the Gulf of Alaska shelf extending from the Islands of Four Mountains to the Chiniak Trough east of Kodiak Island, 14 June to 12 August 2011, in three legs (leg 1, 14-29 June; leg 2, 5-22 July; leg 3, 6-12 August) aboard NOAA Ship Oscar Dyson, a 64 meter stern trawler equipped with acoustic and oceanographic instrumentation. The vessel departed Kodiak, Alaska on 14 June with intermediate port calls in Kodiak, Alaska. An extended port call occurred between legs 2 and 3 (22 July to 6 August) due to vessel mechanical issues. Smaller surveys were also conducted in several bays and around islands including Morzhovoi Bay (22 June), Sanak Trough (23 June), Pavlof Bay (25 June), the Shumagin Islands area (7-8 July), Mitrofania Island (9-10 July), Nakchamik Island (11-12 July), Shelikof Strait (16-21 July), Chiniak Trough (7-8 August), Barnabas Trough (9-10 and 11-12 August), and Alitak Bay (10-11 August). The cruise ended when the vessel arrived in Kodiak, Alaska on 12 August 2011.

Gulf of Alaska Acoustic-Trawl Survey of Walleye Pollock (DY1302, EK60). The Midwater Assessment and Conservation Engineering (MACE) program of NOAA National Marine Fisheries Service (NMFS), Alaska Fisheries Science Center (AFSC) conducted acoustic-trawl (AT) stock assessment surveys in the Gulf of Alaska (GOA) during the winter of 2013 to estimate the distribution and abundance of walleye pollock (Gadus chalcogrammus). The vessel departed Kodiak, Alaska on 7 February, conducted EK60 echosounder system calibration on 9 February, then returned to Kodiak due to vessel mechanical issues on 12 February. The vessel departed Kodiak on 24 February following repairs, arriving at the start of the first survey on 26 February. The Shumagin Islands survey was conducted 26 February to 1 March and included Shumagin Trough, Stepovak Bay, Renshaw Point, Unga Strait, and West Nagai Strait. The Sanak Trough survey was conducted on 2 March, followed by the Morzhovoi Bay survey on 3 March; the vessel arrived in Kodiak on 4 March. The survey was conducted aboard NOAA Ship Oscar Dyson, a 64 meter stern trawler equipped with acoustic and oceanographic instrumentation.

Gulf of Alaska Acoustic-Trawl Survey of Walleye Pollock (DY1303, EK60). The Midwater Assessment and Conservation Engineering (MACE) program of NOAA National Marine Fisheries Service (NMFS), Alaska Fisheries Science Center (AFSC) conducted acoustic-trawl (AT) stock assessment surveys in the Gulf of Alaska (GOA) during the late winter/early spring of 2013 to estimate the distribution and abundance of walleye pollock (Gadus chalcogrammus). The vessel departed Kodiak, Alaska on 14 March arriving at the start of the first survey on 15 March. The Marmot Bay survey was conducted 15-16 March, Shelikof Strait 16-25 March, and Gulf of Alaska shelf break east of Chirikof Island 25-27 March. The vessel arrived in Kodiak 28 March following a post-cruise EK60 calibration on 27 March in Three Saints Bay, Kodiak Island, Alaska. The survey was conducted aboard NOAA Ship Oscar Dyson, a 64 meter stern trawler equipped with acoustic and oceanographic instrumentation.

Gulf of Alaska Acoustic-Trawl Survey of Walleye Pollock (DY1403, 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 Shelikof Strait, Marmot Bay, and Izhut Bay areas of the Gulf of Alaska (GOA) during late winter/early spring of 2014 to estimate the distribution and abundance of walleye pollock (Gadus chalcogrammus). The survey was conducted 13-25 March (Shelikof Strait 15-22 March; Marmot and Izhut Bays 22-24 March), departing from Dutch Harbor, Alaska 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).

Acoustic-Trawl Survey of Walleye Pollock in the Gulf of Alaska (DY1503, 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 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).

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).

Gulf of Alaska Acoustic-Trawl Survey of Walleye Pollock (DY1401, 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 and Sanak Trough areas of the Gulf of Alaska (GOA) during the winter of 2014 to estimate the distribution and abundance of walleye pollock (Gadus chalcogrammus). The survey was conducted 21-28 February (Shumagin Islands 23-27 February; Sanak Trough 26 February), 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).

Gulf of Alaska Acoustic-Trawl Survey of Walleye Pollock (DY1506, 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 Gulf of Alaska (GOA) during late spring/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. The primary instrumentation for the survey was a Simrad EK60 split-beam echosounder system utilizing five frequencies (18, 38, 70, 120, and 200 kHz).

Acoustic-Trawl Surveys of Walleye Pollock in the Gulf of Alaska (DY2017-03). The Midwater Assessment and Conservation Engineering (MACE) program of NOAA Fisheries, Alaska Fisheries Science Center (AFSC) conducted acoustic-trawl (AT) stock assessment surveys in the Gulf of Alaska (GOA) during the winter and early spring of 2017 to estimate the distribution and abundance of walleye pollock (Gadus chalcogrammus). The surveys were 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). The vessel departed Kodiak, Alaska on 14 March and surveyed Spruce Gully and inner Marmot Bay 14-15 March. The vessel returned to Kodiak for an unscheduled port call 15-17 March and departed Kodiak on 18 March. The Shelikof Strait survey was conducted 18-24 March followed by the Chirikof Shelfbreak survey 24-25 March. The outer Marmot Bay survey was conducted on 26 March. A sphere calibration of the echosounder system was conducted in Volcano Bay, Alaska on 14 February and at the end of the current cruise in Izhut Bay, Alaska on 27 March; no significant differences in gain parameters or transducer beam pattern characteristics were noted between the two calibrations. The vessel arrived at its homeport of Kodiak, Alaska on 27 March.