2025 Gulf of Alaska Biennial Bottom Trawl Survey
February 27, 2025
Research brief for the Gulf of Alaska Biennial Bottom Trawl Survey.
Who is conducting the research?
The Groundfish Assessment Program at Alaska Fisheries Science Center of the National Marine Fisheries Service conducts the fishery-independent biennial bottom trawl surveys aboard contracted commercial fishing vessels. Survey teams consist of commercial fishers and Center survey scientists, contractors, and fishery observers.
What is the research objective?
Our objective is to characterize the distribution and abundance of the ecologically and economically important species that live on or near the seafloor in Alaska. Our survey produces observations of species occurrence, species densities, and biological characteristics such as length, sex, age, and food habits. These data collected on our surveys are used to support annual stock assessments and ecological models.
Where is the research being conducted?
This is a survey of the Gulf of Alaska and progresses east from the Islands of Four Mountains to Dixon Entrance, sampling around the Shumagin Islands, Kodiak Island, in lower Cook Inlet, and Southeast Alaska. Trawl samples are collected from the continental shelf and upper slope down to 700 m.
Why are the data important? How will data be used?
This fishery-independent survey provides indexes of abundance along with length and age composition of the populations of economically important fish and crabs species managed by the North Pacific Fishery Management Council. These data are integrated into stock assessments conducted by Center scientists that provide a comprehensive picture of the health of managed populations. Bottom trawl survey results can provide early warnings of unusual increases or decreases in key species, helping to inform management decisions that assure sustainable fisheries.
Related data such as water temperatures, fish body condition, and the relative abundances of prey and other ecologically important species provide ecosystem scientists with the information they need to characterize the overall health of the Gulf of Alaska.