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 (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.

Gulf of Alaska Acoustic-Trawl Surveys of Walleye Pollock (DY1203, 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 2012 to estimate the distribution and abundance of walleye pollock (Theraga chalcogramma). The survey was conducted along the Gulf of Alaska shelf break east of Chrikof Island (17-19 March) and throughout the Shelikof sea valley (20-26 March). The vessel departed Kodiak, Alaska on 5 March for the start of cruise DY1202 and was at sea for the start of the Chirikof shelf break survey. The vessel conducted a personnel transfer in Kodiak on 19 March then proceeded to the Shelikof Strait survey area. A post-cruise EK60 echosounder system calibration was conducted on 26 March in Malina Bay, Afognak Island, Alaska and the vessel returned to Kodiak at the completion of the cruise on 27 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 (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 Surveys of Walleye Pollock (Gadus chalcogrammus) in the Gulf of Alaska (DY1803, EK60). 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 Shelikof Strait and Marmot Bay areas of the Gulf of Alaska (GOA) in the late winter/early spring of 2018 to estimate the distribution and abundance of walleye pollock (Gadus chalcogrammus). This survey was conducted aboard NOAA Ship Oscar Dyson, a 64 meter stern trawler equipped with acoustic and oceanographic instrumentation. The primary acoustic instrument for the survey was a Simrad EK60 split-beam echosounder system utilizing five frequencies (18, 38, 70, 120, and 200 kHz). The vessel conducted an acoustic system calibration in Captains Bay, Dutch Harbor, Alaska on 12 March and departed Dutch Harbor on 13 March transiting toward Shelikof Strait. The Shelikof Strait survey was conducted 15-21 March followed by the Marmot Bay survey 21-22 March. A post-cruise calibration of the echosounder system was conducted at the end of the cruise on 23 March in Kalsin Bay, Kodiak Island, Alaska. The vessel returned to its homeport of Kodiak, Alaska on 23 March ending the cruise.

Acoustic-Trawl Surveys of Walleye Pollock in the Gulf of Alaska (DY1701, EK60). 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). These surveys were conducted aboard NOAA Ship Oscar Dyson, a 64 meter stern trawler equipped with acoustic and oceanographic instrumentation. The primary instrument for the surveys was a Simrad EK60 split-beam echosounder system utilizing five frequencies (18, 38, 70, 120, and 200 kHz). The vessel departed Kodiak, Alaska on 7 February and conducted the Shumagin Islands survey (including Shumagin Trough from Renshaw Point to Simeonof Island, Stepovak Bay, Unga Strait, and West Nagai Strait) 8-11 February. The Sanak Trough survey was conducted on 11 February followed by the Morzhovoi Bay survey on 12 February. The vessel transited to Pavlov Bay and conducted the Pavlov survey 13-14 February. A calibration of the echosounder system was conducted on 14 February in Volcano Bay, Alaska. The vessel returned to its homeport of Kodiak, Alaska on 16 February, 2017.

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 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.