California Current Ecosystem Survey 2006. The 2006 California Current Ecosystem Survey used two vessels: the NOAA FSV Oscar Dyson and the NOAA FRV David Starr Jordan. The plan was for the FSV Oscar Dyson was to survey the northern part and the FRV David Starr Jordan to survey the southern part using identical methods. However, equipment failures prevented trawling operations on the FRV David Starr Jordan, and trawling was only conducted from the FSV Oscar Dyson and the survey plan of the FSV Oscar Dyson was extended to cover the entire West Coast down to San Diego, California. Both vessels collected water samples from a CTD-rosette, ichthyoplankton samples from plankton nets and meteorological data from weather station sensors at prescribed and adhoc stations. At some of these and other locations, surface trawls were collected during night from the FSV Oscar Dyson. Underway operations on each ship included operating a continuous underway fish egg sampler (CUFES), an acoustic Doppler current profiler (ADCP), multiple-frequency split-beam echosounders and a multi-beam echosounder. Daytime underway operations included bird and mammal observations. The acoustic surveys were accomplished using Simrad EK60 split-beam echosounders. Four echosounders were operated on the David Starr Jordan at 38, 70, 120 and 200 kHz, and five were operated on the Oscar Dyson at 18, 38, 70, 120 and 200 kHz. Each 5 echosounder was calibrated prior to the survey using the standard sphere method.

The Midwater Assessment and Conservation Engineering (MACE) program of NOAA Fisheries (NMFS), Alaska Fisheries Science Center (AFSC), conducted an acoustic-trawl (AT) stock assessment survey in the Southeastern Aleutian Basin near Bogoslof Island 18-25 February 2024, to estimate distribution and abundance of walleye pollock (Gadus chalcogrammus). The 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). The vessel departed Kodiak, Alaska on 18 February and conducted the survey between 167°and 170° W 23-25 February. A calibration of the EK80 echosounder system was conducted at the start of the previous survey (DY2401) on 4 February in Kalsin Bay, Kodiak Island, Alaska. Trawl operations were conducted using an LFS1421 mid-water trawl net equipped with a Kongsberg FS70 trawl sonar.

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 Shelikof Strait, Chirikof Shelfbreak, and Marmot Bay areas of the Gulf of Alaska (GOA) in the late winter of 2023 to estimate 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). The vessel departed Kodiak, Alaska on 4 March and conducted the Shelikof Strait survey 4-11 March, followed by the Chirikof Shelfbreak survey 11-14 March, and Marmot Bay 15-16 March. A calibration of the EK80 echosounder system was conducted prior to starting the previous survey on 12 February; a post-cruise calibration was conducted 13 March in Kaiugnak Bay, Kodiak Island, Alaska. Trawl operations were conducted using an LFS1421 mid-water trawl net.

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 Shumagin Islands, Pavlof Bay, Morzhovoi Bay, and Sanak areas of the Gulf of Alaska (GOA) 10-22 February 2023, to estimate distribution and abundance of walleye pollock (Gadus chalcogrammus). The 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). The vessel departed Kodiak, Alaska on 10 February and conducted the survey 14-20 February. A calibration of the EK80 echosounder system was conducted prior to starting the survey on 12 February Uyak Bay, Kodiak Island, Alaska. Trawl operations were conducted using an LFS1421 mid-water trawl net.

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 areas of the Gulf of Alaska (GOA) in the summer of 2023 to estimate 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). The survey was conducted in three segments (10-22 June, 30 June to 21 July, and 7-20 August) starting and ending in Kodiak, Alaska with two port calls also in Kodiak. The vessel departed Kodiak, Alaska on 11 June and conducted a standard sphere calibration on the Kongsberg EK80 echosounder system on 11 June in Uyak Bay, Kodiak Island, Alaska. The survey areas included the Gulf of Alaska Shelf (between 14 June and 17 August), the Shumagin Islands (18-20 June), Shelikof Strait (1-8 July), Barnabas Trough (15-18 July), and Chiniak Trough (19-21 July). A second calibration of the EK80 echosounder system was conducted on 12 August in North Arm, Nuka Sound, Kenai Peninsula, Alaska. Mid-water trawl operations were conducted using an LFS1421 mid-water trawl net. Water column CTD casts were conducted at select positions on most days throughout the cruise using a Sea-Bird Scientific SBE 911Plus water column profiling system. During the second segment of the cruise, experimental operations were conducted using an iXblue DriX unmanned surface vessel (USV) remotely operated from the vessel and/or shore stations. The USV was equipped with a Kongsberg EK80 echosounder system. Survey operations were concluded on 18 August and the vessel returned to port (Kodiak) on 20 August.

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) 1 June to 10 July 2021 to estimate the distribution and abundance of walleye pollock (Gadus chalcogrammus). The survey was conducted along the Gulf of Alaska shelf from the Islands of Four Mountains to Yakutat Trough. Survey operations were conducted aboard NOAA Ship Oscar Dyson, a 64 meter fisheries research vessel built in 2003 and equipped for stern trawling and included capabilities to collect acoustic, oceanographic, and biological scientific data. Acoustic data was collected for the survey using a Kongsberg Simrad EK80 split-beam echosounder system utilizing five frequencies (18, 38, 70, 120, and 200 kHz). Mid-water trawls were conducted using an LFS 1421 mid-water trawl net equipped with a Kongsberg Simrad FS70 trawl sonar. The survey was divided into two segments with the first segment conducted from 1 June to 20 and the second segment conducted 24 June to 10 July with a mid-survey port call in Kodiak. The vessel departed Kodiak, Alaska on 1 June and conducted a calibration of the EK80 system prior to starting survey operations. The survey areas included the Gulf of Alaska shelf from the Islands of Four Mountains to southeast Kodiak Island, the Shumagin Islands, Barnabas Trough, Shelikof Strait, Chiniak Trough, and the Gulf of Alaska shelf from southeast Kodiak Island to Yakutat Trough. A post-survey calibration of the EK80 echosounder was completed prior to arrival in Kodiak, Alaska on July 10.

Spring 2009 CalCOFI. The California Cooperative Oceanic Fisheries Investigations (CalCOFI) are a unique partnership of the California Department of Fish and Wildlife, NOAA Fisheries Service and Scripps Institution of Oceanography. The organization was formed in 1949 to study the ecological aspects of the sardine population collapse off California. Today our focus has shifted to the study of the marine environment off the coast of California, the management of its living resources, and monitoring the indicators of El Nino and climate change. CalCOFI conducts quarterly cruises off southern and central California, collecting a suite of hydrographic and biological data on station and underway. Data collected at depths down to 500 m include: temperature, salinity, oxygen, phosphate, silicate, nitrate and nitrite, chlorophyll, transmissometer, PAR, C14 primary productivity, phytoplankton biodiversity, zooplankton biomass, and zooplankton biodiversity.

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.

The Midwater Assessment and Conservation Engineering (MACE) program of NOAA Fisheries (NMFS), Alaska Fisheries Science Center (AFSC), conducted acoustic-trawl (AT) stock assessment surveys in the Shumagin Islands and Pavlof Bay areas of the Gulf of Alaska (GOA) 4-12 February, 2024, to estimate distribution and abundance of walleye pollock (Gadus chalcogrammus). The 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 these surveys was a Kongsberg EK80 split-beam scientific echosounder system utilizing five frequencies (18, 38, 70, 120, and 200 kHz). The vessel departed Kodiak, Alaska on 4 February and conducted the Shumagin Islands survey 6-11 February, and the Pavlof Bay survey 9-10 February. A calibration of the EK80 echosounder system was conducted following vessel departure from Kodiak and prior to starting the survey on 4 February in Kalsin Bay, Kodiak Island, Alaska. Trawl operations were conducted using an LFS1421 mid-water trawl net equipped with a Kongsberg FS70 trawl sonar.

The Midwater Assessment and Conservation Engineering (MACE) program of NOAA Fisheries (NMFS), Alaska Fisheries Science Center (AFSC), conducted acoustic-trawl (AT) stock assessment surveys in the Shelikof Strait and Chirikof Shelf break areas of the Gulf of Alaska (GOA) 5-20 March, 2024, to estimate distribution and abundance of walleye pollock (Gadus chalcogrammus). The surveys were 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 these surveys was a Kongsberg EK80 split-beam scientific echosounder system utilizing five frequencies (18, 38, 70, 120, and 200 kHz). The vessel departed Kodiak, Alaska on 5 March and conducted the Shelikof Strait survey 6-17 March, and the Chirikof Shelf break survey 17-19 March. A calibration of the EK80 echosounder system was conducted during a previous survey (DY2401) on 4 February in Kalsin Bay, Kodiak Island, Alaska, and a post-survey calibration was conducted in Uyak Bay, Kodiak Island, Alaska, on 9 March. Trawl operations were conducted using an LFS1421 mid-water trawl net equipped with a Kongsberg FS70 trawl sonar.