Near Real-time Temperatures From The Bering Sea Bottom Trawl Surveys 2022

As in past years, NOAA Fisheries scientists are sharing information on ocean temperatures recorded during the Eastern Bering Sea and Northern Bering Sea Bottom Trawl Surveys in 2022.

Alaska

Survey Progress and Bottom Temperatures

Bering Sea bottom temperature map showing temperature from cold (blue) to warm (red). — Near real-time ocean bottom temperatures collected May 29-August 20 2022 during the Eastern Bering Sea (May 25-Aug 03 2022) and Northern Bering Sea (Aug 03-Aug 28 2022) surveys aboard the F/V Vesteraalen and F/V Alaska Knight. On August 20, stations R-01 (60.667°N, -168.008°W; >8°C), R-02 (60.667°N, -167.323°W; >8°C), and R-18 (60.667°N, -168.693°W; >8°C) were surveyed by the F/V Alaska Knight. There are 0 stations planned for August 21. Data have NOT been through final review. Final, validated data (e.g., temperature and species collected at each station), will be publicly accessible on FOSS platform. Credit: NOAA Fisheries

Survey Mission

During our Eastern Bering Sea and Northern Bering Sea Bottom Trawl Surveys the primary goal is to collect data on the distribution and abundance of crab, groundfish, and other bottom-dwelling species in the Bering Sea. These data are used for ecosystem monitoring and to aid in the management of commercially important species in Alaska.

NOAA Fisheries has conducted the eastern Bering Sea Shelf survey annually since 1975, and formally standardized the survey in 1982. Since then, we have only missed one opportunity to survey the eastern Bering Sea in 2020 due to the COVID-19 pandemic. The northern Bering Sea Shelf survey has only been surveyed in 2010, 2017, 2019 and 2021.

Survey Dates

The eastern Bering Sea bottom trawl survey is being conducted from May 25 to August 2. The northern Bering Sea bottom trawl survey will be conducted from about August 3 to 28. This year, start dates are staggered for the two vessels conducting the survey, the F/V Vesteraalen (departing Dutch Harbor on 25 May) and the F/V Alaska Knight (departing Dutch Harbor on 26 May), and due to COVID-related concerns, port calls will again be minimized.

Once scientists complete this year’s survey of the eastern Bering Sea, they will move northward to conduct a full survey of the northern Bering Sea bottom-dwelling community. Additional surveys are planned in the northern Bering Sea using surface trawls and hydro-acoustics to monitor key components of the marine ecosystem and environmental conditions.

For the safety of our survey teams and vessel crews and the communities of Alaska, we have again canceled outreach events typically associated with our port calls during the survey. However, as in recent years, we intend to provide regular survey updates on water temperatures collected near the seafloor at all of our survey stations.

Survey Importance

Collecting environmental data while on the survey helps us better understand the organisms’ habitats and the greater ecosystem. Water temperature is important to many species. It affects their spawning times, access to food, growth rates, and their overall distribution patterns.

Concerns remain regarding overall water temperature and the extent of the cold pool. The cold pool is a natural, thermal barrier created by winter sea ice that persists throughout the subsequent summer across the eastern and northern Bering Sea shelf. The cold pool is comprised of water with temperatures below 2°C. Increased cold pool coverage in 2020-2021 follows the record low coverage observed in 2017-2019.

The size and distribution of the cold pool has major implications for species and the environment, alike. The cold pool tends to separate Arctic species usually found in the northern and eastern Bering Sea from commercially important stocks like walleye pollock and Pacific cod. The cold pool was greatly reduced during the summers of 2017-2019. Fish distribution patterns changed profoundly, with new significant proportions of the walleye pollock and Pacific cod stocks observed in the northern Bering Sea. For more information about the cold pool and details on how timing effects may influence the mean temperature results, please refer to our ecosystem status report.

Mean bottom temperatures in the eastern Bering Sea from 1982-2021 and the northern Bering Sea from 2010-2021 can provide a brief understanding of how temperatures collected this year compare to temperatures collected in the past.

Map showing average bottom ocean temperatures from 2010 to 2021. — Mean bottom temperatures from NOAA Fisheries 2022 Bottom Temperature Mean and EBS 1962-2021 (39 years) and NBS 2010-2021 (4 years) in 2022. Credit: NOAA Fisheries.

Be sure to check back here for regular updates on ocean temperatures collected during the Bering Sea bottom trawl surveys. The final, validated survey data, including temperature and species collected at each station among other observations, will be made publicly accessible about a month after the survey is complete on the Fisheries One Stop Shop (FOSS) platform after the data has undergone the post-survey data review process.

Downloadable PDF

PDF (60 pages as of August 4, 2022.)

Document updates automatically 7 days per week for duration of survey unless ships are at port.

This PDF provides static maps of each day's progress and bottom temperatures (Celsius). The last page includes a map of the full eastern and northern Bering Sea survey grid with bathymetry at 50m, 100m, and 200m.