Earlier this spring, the Alaska Department of Fish and Game announced a low forecast for chinook or king salmon on the Stikine River near Wrangell and Petersburg. Just over 18,000 fish are expected to return this year. In turn, residents will be limited to a one-bag limit for the popular derby contest fish.
King runs on the Stikine have been declining for several years. Sport Fish Research Biologist Troy Jaecks explained during a public presentation Thursday there is plenty we know about trends on the river.
“On the Stikine River in particular, we have a pretty good estimate or straight up count of all the things you see here, escapement, the fresh water harvest, terminal harvest here in district 108, marine harvest which is troll and other purse-seine fisheries and things that might happen to catch fish outside of district 108,” Jaecks listed. “Through doing the smolt project where we tag these little itty-bitty guys, we also know how many fish go out.”
King salmon typically spend one year in fresh water before smolting and heading out to the ocean for up to five years. Jaecks explains that between a mark-and-recapture initiative and other projects used to estimate runs, fish are returning sooner rather than later, giving the perception of smaller fish. Three and four-year fish are able to spawn, and with four-year fish becoming rarer, predicting the run is becoming harder.
“One of the beauties of Chinook, despite the fact that they spend all that time out there and subject themselves to all that potential mortality over time, is that there’s multiple year classes coming back each year,” Jaecks said. “If all your eggs are in one basket because we only have three-ocean fish and they’re the only ones that have any females, all of a sudden if that brood year happens to fail, then we start seeing this greater variability of returns.”
There is no clear answer why fish are spending less time in salt water. To further complicate the issue, survival rates of kings in the ocean have also been cut in half since 2001, down from about 4 percent.
“Lots of things can happen over five years. They travel thousands of miles, potentially repeatedly. Some archival tags on these things have shown them go down to 300 meters,” Jaecks noted. “It’s bizarre, chinook are just fascinating in the things that they can do and the places they go. It makes it difficult once they hit the ocean to know what’s going on.”
Jaecks added there is research being conducted to better understand what’s happening in salt water, but no smoking gun has been found. He explained these things can be cyclical, but there’s no solid timeline for when king runs will be up again.