Near Real-time Temperatures from the Eastern Bering Sea Bottom Trawl Survey 2024

Survey Progress and Bottom Temperatures

The goal of the eastern Bering Sea bottom trawl surveys are to collect data on the ranges and populations of fish, crab, and other bottom-dwelling species in the Bering Sea. Temperature heavily influences these ranges and populations, so ocean bottom temperatures are recorded from all the areas the survey collects catch samples. During this year's surveys, we are sharing these temperatures in near real-time. NOAA Fisheries has annually conducted this survey since 1982, except in 2020, making this the longest-running (42 years!), standardized time series of fish and invertebrate data in the region. 

All data collected on these surveys are and will be publicly accessible from: 

• Fisheries One Stop Shop (FOSS) public data portal
• Distribution Mapping and Analysis Portal (DisMAP) 
• Alaska Fisheries Information Network (AKFIN)

This PDF  (and the color-blind friendly version PDF) provides static maps of each day's progress and bottom temperatures (degrees Celsius; °C). The last page includes a map of the full eastern Bering Sea survey grid with bathymetry at 50 m, 100 m, and 200 m.  

Survey Dates

This year, the eastern Bering Sea bottom trawl survey will be conducted from May 24 to August 20 aboard the F/V Alaska Knight and the F/V Northwest Explorer. We will keep the communities informed of our survey progress by posting daily updates of our survey progress via the website and social media.  Look out for preliminary results from the survey in our fall University of Alaska Fairbanks Strait Science Seminar, radio and newspaper interviews, and the September Joint Groundfish Plan Team presentation.

Survey Location

The eastern Bering Sea bottom trawl survey begins in Dutch Harbor, Alaska, where the vessels transition to eastern Bristol Bay to begin sampling. From Bristol Bay, the survey proceeds westward completing north-south columns of the survey on their way to the shelf edge. The east-to-west survey progression is based on an understanding of historical trends in fish movement and is intended to ensure the survey moves in the opposite direction of the seasonal on-shelf (eastward) migration patterns typical of yellowfin sole and other species. 

Bering Sea Cold Pool

Each spring, a cold pool is formed by the previous winter’s melted sea ice in the Bering Sea. The location and temperature of this cold pool changes from year to year and affects fish, crab, and other bottom-dwelling species movement and ranges. Due to warming ocean temperatures in the Bering Sea, scientists track and closely monitor the location of the cold pool by collecting ocean bottom temperatures at each station. The area that the cold pool covers is represented by the cold pool extent index, which is defined as the total area of the eastern Bering Sea survey area where bottom temperatures are less than or equal to 2°C, in units of square kilometers (km²). Mean bottom temperatures can help us compare temperatures this year to temperatures of the past, and understand how those temperatures have changed over time. Learn more about temperature anomalies, the cold pool, and how these temperatures have changed over time. 

Pictures from the field

What does survey life and research look like? Explore our photo gallery to see this current survey’s photos from scientists in the field. These photos show the incredible places that NOAA scientists go and showcase our mission in ways that words cannot.