The Midwater Assessment and Conservation Engineering (MACE) program of NOAA Fisheries, Alaska Fisheries Science Center (AFSC), conducted an acoustic-trawl (AT) stock assessment survey on the Easter Bering Sea shelf from Bristol Bay to U.S.-Russia Convention Line in the late spring and summer of 2022 to estimate the distribution and abundance of walleye pollock (Gadus chalcogrammus). This survey was conducted aboard NOAA Ship Oscar Dyson (built in 2003, 64 meters, 2500 tons, 3100 hp), a research stern trawler equipped with acoustic and oceanographic instrumentation. The primary water column acoustic instrument for the survey was a Kongsberg EK80 split-beam scientific echosounder system utilizing five frequencies (18, 38, 70, 120, and 200 kHz). Trawl operations were conducted using an LFS1421 mid-water trawl net. The survey was conducted in three legs starting and ending in Dutch Harbor, Alaska with intermediate port calls in Dutch Harbor. Survey leg 1 was conducted 3-15 June, leg 2 was 22 June to 8 July, and leg 3 was 20 July to 5 August; the dates listed are for actual survey operations and do not include the additional transit time between port and area of operations. The delay between legs 2 and 3 was due to vessel staffing issues. Calibrations of the EK80 echosounder system were conducted prior to starting the survey (31 May), at the end of leg 2 (9 July), and at the end of the survey (5 August) in Captains Bay, Unalaska Island (Dutch Harbor), Alaska.

Southeastern Aleutian Basin (Bogoslof Island) Acoustic-Trawl Survey of Walleye Pollock (DY1402, 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 Bogoslof Island area of the southeastern Aleutian Basin during late winter of 2014 to estimate the distribution and abundance of walleye pollock (Gadus chalcogrammus). The survey was conducted 7-11 March, departing from Kodiak, Alaska (3 March) and arriving in Dutch Harbor, Alaska (11 March). 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).

Southeastern Aleutian Basin (Bogoslof Island) Acoustic-Trawl Survey of Walleye Pollock (DY1202, 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 Bogoslof Island area of the southeastern Aleutian Basin during the winter of 2012 to estimate the distribution and abundance of walleye pollock (Theraga chalcogramma). The surveys were conducted 5-15 March, departing from Kodiak, Alaska (4 March) and returning to Kodiak at the end of cruise DY1203 on 27 March; an intermediate personnel transfer was conducted in Kodiak on 19 March. The surveys were conducted aboard NOAA Ship Oscar Dyson, a 64 meter stern trawler equipped with acoustic and oceanographic instrumentation.

Acoustic-Trawl Survey of Walleye Pollock (Gadus chalcogrammus) in the Southeastern Aleutian Basin near Bogoslof Island (DY1802, EK60). The Midwater Assessment and Conservation Engineering (MACE) program of NOAA Fisheries, Alaska Fisheries Science Center (AFSC) conducted an acoustic-trawl (AT) stock assessment survey in the southeastern Aleutian Basin near Bogoslof Island during the winter 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 departed Kodiak, Alaska on 1 March transiting toward the southeast Aleutian Basin 1-3 March. The survey was conducted in the Bogoslof Island area 3-7 March, with the vessel arriving in Dutch Harbor, Alaska on 7 March. A calibration of the echosounder system was conducted at the end of the previous cruise on 14 February in Kalsin Bay, Kodiak Island, Alaska.

Southeastern Aleutian Basin (Bogoslof Island) Acoustic-Trawl Survey of Walleye Pollock (DY1603, 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 Bogoslof Island area of the southeastern Aleutian Basin during late winter of 2016 to estimate the distribution and abundance of walleye pollock (Gadus chalcogrammus). The surveys were conducted 4-8 March, departing from Kodiak, Alaska (2 March) and included the Umnak and Samalga Pass area. The vessel returned to the Kodiak, Alaska area on 13 March to exchange scientific personnel and depart for the following cruise (Gulf of Alaska/Shelikof Strait survey, 14-21 March, cruise DY1604). The survey was conducted aboard NOAA Ship Oscar Dyson, a 64 meter stern trawler equipped with acoustic and oceanographic instrumentation.

Acoustic-Trawl Survey of Walleye Pollock on the U.S. and Russian Bering Sea Shelf (DY1207, 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 on the U.S. and Russian Bering Sea shelf during late spring/summer of 2012 to estimate the distribution and abundance of walleye pollock (Theraga chalcogramma). The survey was conducted from Bristol Bay, eastern Bering Sea in the U.S. to Cape Navarin, Russia, 7 June to 10 August aboard NOAA Ship Oscar Dyson, a 64 meter stern trawler equipped with acoustic and oceanographic instrumentation. The vessel departed Dutch Harbor, Alaska on 7 June and returned to Dutch Harbor on 10 August. The cruise was completed in three legs (leg 1, 7-25 June; leg 2, 30 June to 18 July; leg 3, 23 July to 10 August), with all port calls in Dutch Harbor, Alaska. The EK60 echosounder system was calibrated prior to and at the end of the cruise in Captains Bay, Dutch Harbor, Alaska.

Acoustic-Trawl Survey of Walleye Pollock on the Eastern Bering Sea Shelf (DY1407, EK60). National Marine Fisheries Service (NMFS), Alaska Fisheries Science Center (AFSC) conducted an acoustic-trawl (AT) stock assessment survey on the eastern Bering Sea shelf during late spring/summer of 2014 to estimate the distribution and abundance of walleye pollock (Gadus chalcogrammus). The survey was conducted from Bristol Bay in the U.S. to Cape Navarin, RusThe Midwater Assessment and Conservation Engineering (MACE) program of NOAA sia, 12 June to 13 August aboard NOAA Ship Oscar Dyson, a 64 meter stern trawler equipped with acoustic and oceanographic instrumentation. The vessel departed Dutch Harbor, Alaska on 12 June and returned to Dutch Harbor on 13 August. The cruise was completed in three legs (leg 1, 12-30 June; leg 2, 4-22 July; leg 3, 26 July to 13 August), with all port calls in Dutch Harbor, Alaska. 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 on the U.S. and Russian Bering Sea Shelf (DY1006, 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 on the U.S. and Russian Bering Sea shelf during late spring/summer of 2010 to estimate the distribution and abundance of walleye pollock (Theragra chalcogramma). The survey was conducted from Bristol Bay, eastern Bering Sea in the U.S. to Cape Navarin, Russia, 7 June to 10 August aboard NOAA Ship Oscar Dyson, a 64 meter stern trawler equipped with acoustic and oceanographic instrumentation. The vessel departed Kodiak, Alaska on 5 June and arrived in Dutch Harbor on 7 August. The cruise was completed in three legs (leg 1, 5-24 June; leg 2, 29 June to 16 July; leg 3, 20 July to 7 August), with port calls in Dutch Harbor, Alaska; a personnel exchange occurred in Dutch Harbor on 18 June. Fisheries research operations were conducted on Snakehead plateau south of Kodiak Island 7-9 June and again in the Bering Sea 3-5 August. The EK60 echosounder system was calibrated at the start of the cruise in Three Saints Bay, Kodiak Island, Alaska 5-6 June, and at the end of the cruise in Anderson Bay, Unalaska Island, Alaska 6-7 August.

Echo Integration-Trawl Survey of Walleye Pollock (Theraga chalcogramma) on the U.S. and Russian Bering Sea Shelf (OD2008-09). 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 on the U.S. and Russian Bering Sea shelf during late spring/summer of 2008 to estimate the distribution and abundance of walleye pollock (Theragra chalcogramma). The survey was conducted from Bristol Bay, eastern Bering Sea in the U.S. to Cape Navarin, Russia, 2 June to 31 August aboard NOAA Ship Oscar Dyson, a 64 meter stern trawler equipped with acoustic and oceanographic instrumentation. The vessel departed Dutch Harbor, Alaska on 2 June and arrived in Dutch Harbor on 31 July. The cruise was completed in three legs (leg 1, 2-19 June; leg 2, 21 June to 10 July; leg 3, 11-31 July), with port calls in Dutch Harbor, Alaska. Experimental and research gear operations were conducted during non-daylight hours and paired trawl net codend comparison experiments and intervessel comparison studies were conducted with NOAA Ship Miller Freeman 20-28 July. The Simrad EK60 scientific echosounder system is the primary acoustic instrument installed on the Dyson and was calibrated at the start of the cruise in Captains Bay, Unalaska Island, Alaska on 2 June, mid-cruise in Captains Bay on 11 July, and at the end of the cruise in Nateekin Bay, Unalaska Island, Alaska on 31 July.

Acoustic-Trawl Survey of Walleye Pollock in the Eastern Bering Sea (DY1608, 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 on the eastern Bering Sea shelf during late spring/summer of 2016 to estimate the distribution and abundance of walleye pollock (Gadus chalcogrammus). The survey was conducted 12 June to 17 August aboard NOAA Ship Oscar Dyson, a 64 meter stern trawler equipped with acoustic and oceanographic instrumentation. The vessel departed Dutch Harbor, Alaska on 12 June and returned to Dutch Harbor on 17 August. The cruise was completed in three legs (leg 1, 12 June to 3 July; leg 2, 7-25 July; leg 3, 29 July to 17 August), with all port calls in Dutch Harbor, Alaska.