Fisheries Service speeds up reporting time for salmon bycatch in the Bering Sea

New technology will help speed up the turnaround time for genetic data on the salmon bycatch in Bering Sea fisheries, which could help managers and fishermen make more informed decisions about how and where to best avoid those salmon.

Scientists at the Alaska Fisheries Science Center, part of the National Marine Fisheries Service, regularly release genetic breakdowns of the salmon bycatch by the commercial fishing fleet in the Bering Sea. That genetic data helps inform managers about which stocks of salmon are being caught in high-seas fisheries, which can be important for helping to conserve stocks that are less abundant. However, that data has been complex and slow to produce for a long time—until recently, it’s taken about 18 months from collection to release, which means that data is about two seasons out. 

Now, scientists can turn around that same data in about six months. Wes Larson, the program manager for the Alaska Fisheries Science Center’s genetics program, said the way it’s gone in the past, Chinook salmon data from 2022 would normally have come out in 2024; now, it should come out in June 2023.

“As federal scientists, we get to work with the observers, but they only get data so fast,” he said. “It's a lot different than (the Alaska Department of Fish and Game), who get samples in-season. For chum, for example, the chum all get caught between June and September, but we don't see the samples in our lab until March.”

The salmon samples are collected by on-board observers on the commercial fishing vessels — typically, the trawlers fishing for pollock. Then, when the vessel docks, the samples are turned over to collectors, who then pass it to NMFS. In the past year, the scientists have worked on incorporating a new technology called Genotyping-in-Thousands to the labs, to process much larger groups of individual salmon than in the past. 

“Essentially just more efficiently— (it processes) more samples more efficiently,” he said. “We do process a few more than we used to, and also the flexibility that the new software uses allow us to slice it and dice it to look at more variables.”

Bycatch is defined as any species of fish caught in a fishery that is not a target species—essentially, anything the fishery is not allowed to keep or can’t sell. Chinook and chum salmon are frequently taken as bycatch in the Bering Sea pollock fishery, and while many stocks are represented in it, the fishery has drawn a lot of attention because it includes Yukon and Kuskokwim river salmon stocks. Those two stocks have seen massive shortfalls in the last few years—so much so that subsistence and targeted commercial fishing have been closed, but the fish are still taken as bycatch.

In 2021, directed pollock fisheries in the Bering Sea/Aleutian Islands caught about 543,043 chum salmon as bycatch and about 13,783 Chinook salmon. Only a small percentage of those — about 9.4%, according to NMFS — came from Western Alaska rivers like the Yukon and Kuskokwim, but with complete closures due to salmon shortfalls in the subsistence and directed fisheries, many fishermen have cried foul at management meetings.

In response, Alaska Native tribal representatives have called for hard caps on salmon bycatch in the pollock fishery, among other restrictions, which so far the North Pacific Fishery Management Council has declined to set. The council has established a new Salmon Bycatch Committee, which is currently seeking nominations for membership through Sept. 30. The committee would focus on bycatch issues that affect the council’s management of salmon bycatch in the Bering Sea pollock fishery, with representation both from the commercial industry and from communities in Western Alaska. Appointments are due to be announced at the upcoming council meeting from Oct. 3-5 in Anchorage.

Separately, Gov. Mike Dunleavy also commissioned a Bycatch Review Task Force at the state level to review and make recommendations about how to manage bycatch in the state’s various commercial fisheries. That task force is due to produce recommendations at the end of this year.

Managers can use some of the bycatch data to help establish where salmon move, but if it’s not in real time, it can’t be responsive to in-season trends. One of the long-term possibilities for this data to is to build a predictive model — essentially, looking at patterns of salmon stock movements in the Bering Sea and using that data to help determine best practices for avoiding those stocks, Larson said.

NMFS has established some patterns already in the Bering Sea chum salmon fishery.In general, most of the fish caught as bycatch in the Bering Sea are from Northeast Asia or the eastern Gulf of Alaska/Pacific Northwest region. Asian fish tend to be caught further west and earlier in the summer season, while the other stocks are further east and caught later. Some of the data shows so far that Western Alaska chum salmon may be more likely to be caught earlier in the summer and further east, but NMFS wants more data for more modeling. 

Western Alaska’s stock of king salmon were the biggest contributor to bycatch in 2020, with a little more than half of the king salmon caught coming from there, according to NFMS. That tracks with the trend since 2017, which has seen more and more of the king salmon in bycatch coming from Western Alaska.

The North Pacific Fishery Management Council is scheduled to meet in Anchorage starting Oct. 3. However, a more detailed report about chum salmon bycatch in the Bering Sea isn’t expected until the council’s December meeting. 

Reach Elizabeth Earl at [email protected].

Updated: 
10/05/2022 - 3:17pm