September 14, 2021

Scientists and the industry as a whole got a shocking look at survey numbers for snow crab late last week and heard discussion on it yesterday during the first day of the week-long Crab Planning Team. Declining numbers of snow crab compared to 2019, when the last survey was taken, have scientists, managers, and industry members grappling with the numbers they have and the far larger set of information they don't have.

Male snow crab abundance in the eastern Bering Sea is down 70% from 2018, a decline of 2.7 billion animals. Recruitment is worse: the abundance of immature males (less than 95 mm carapace width) is down 96% in the eastern Bering Sea, a decline of 5.5 billion individuals.

The story is much worse for female snow crab. Adult abundance is down 70% or by about 2.7 billion animals. Recruitment or the abundance of immature female snow crab is down by 99% from 2018, a loss of 2.6 billion female juvenile snow crab.

How, why, at what age, and where are unanswered questions despite ongoing research and investigations at NOAA Fisheries, Alaska Department of Fish and Game, and at several universities and research foundations. The cold pool, a part of the Bering Sea where cold water creates a barrier for pollock, cod, and other species to follow as it moves, has shrunk in size and time during the winter allowing migration north for groundfish and crab. The nutrients that are associated with sea ice, which is also diminishing due to ocean warming in the Bering Sea, are no longer available in many areas where young snow crab, also called opilio, have traditionally relied on for food. 

The news on tanner crab is better. 

“Abundance estimates declined slightly for mature male Tanner crab (C. bairdi) east and west of 16o W, with the largest declines seen in the industry preferred [larger] size class. In contrast, estimates of mature female Tanner crab abundance increased, especially east of 16o W. Abundance estimates for all immature Tanner crab declined, except for immature males east of 166o W,” according to the 2021 Eastern Bering Sea Continental Shelf Trawl Survey: Results for Commercial Crab Species.

The report will be presented today at the Crab Plan Team week-long meeting, a sort of peer-review that then goes to the Science and Statistical Committee of the North Pacific Fisheries Management Council. On October 6 the Council will determine a management approach to the upcoming season and shortly thereafter Alaska’s Department of Fish and Game will release catch limits on all species. 

Photo Credit: Foodio / Shutterstock.com

Peggy Parker
SeafoodNews.com
1-781-861-1441
peggyparker@urnerbarry.com