Tuesday September 2, 2025
Yukon News —
The Whitehorse Fish Ladder has seen 685 Chinook salmon pass through as of Aug. 29: while the number is significantly surpassed last year’s numbers, experts say there’s still a long way to go for a healthy Chinook population along the Yukon River.
Last year, by Aug. 26, 268 Chinook had passed through the fish ladder: a season total of just under 500 Chinook would pass through by the end of the season. This year, Aug. 26 had already seen 675 Chinook pass through the site — which is higher than the 10-year average of 578 for the fish ladder.
According to the Department of Fisheries and Oceans, Chinook salmon in the Yukon River have experienced declining populations. In 2022 and 2023, Chinook populations hit an all-time low, which led to the Alaskan and Canadian governments agreeing in 2024 to impose a moratorium on Chinook salmon fishing in the Yukon River in for a full salmon life cycle of seven years.
But there’s more beneath the surface of the higher numbers being seen at the Whitehorse Fish Ladder.
Dennis Zimmermann, the chair of the Yukon Salmon Sub-committee, told the News that the number of females within the run is quite low.
“You need females. Females are more important than males, because they carry the eggs,” Zimmermann said.
According to the Aug. 28 in-season update for the Yukon River Chinook salmon from the federal Department of Fisheries and Oceans, female fish made up 38.8 per cent of Chinook salmon passing through the Pilot Station sonar in the lower Yukon River as of July 29.
However, the proportion of Chinook salmon crossing at the Whitehorse fish ladder is very low, according to Adam O’Dell, Yukon River senior biologist with the federal Department of Fisheries and Oceans
“There is still relatively few females coming through, and those females are the ones that are going to be promoting the redd building,” O’Dell said. Redds refer to salmon nests.
Furthermore, the majority of Chinook salmon crossing through the fish ladder are hatchery fish, said O’Dell. They make up 66 per cent of the Chinook crossing over to date, whereas the run is usually split between wild and hatchery fish, he said.
The return might be supplemented by a high hatchery return this year, and a high male hatchery return at that, O’Dell said.
Furthermore, it’s been a low female return, O’Dell said, which is alarming, as females grow the population. “So a low female return is not a good sign.”
There are multiple sites along the Yukon River where scientists count Chinook salmon swimming through. These sites are showing low returns, O’Dell said.
The overall number of salmon entering Canada along the main stem of the Yukon River is essentially the same as it was last year, he said.
In 2024, 24,183 Chinook salmon swam past the Eagle assessment site downstream of the United States-Canada border near Eagle, Alaska as Aug. 27. As of Aug. 27, 2025, the number of Chinook swimming past that site was 23,806. The 10-year average for this station was 44,879 Chinook salmon.
According to O’Dell, the number of Chinook passing the Klondike River sonar is lower than last year(184 as opposed to 276 as of Aug. 21), whereas the Pelly River sonar is higher than 2024 (3,033 as opposed to 2,548 as of Aug. 26).
The Big Salmon Sonar is seeing a higher number of Chinook than last year (3,027, as opposed to 1,831 as of Aug. 25) and the Tatchun River Video Weir has counted fewer Chinook salmon this year than last year (151 as opposed to 371 as of Aug. 27).
But all of those numbers are much less than long-term averages, O’Dell said. “Overall, we’re still continuing to see a lot fewer fish.”
Zimmerman said that not all Chinook that enter the mouth of the Yukon River are meant to make it to the fish ladder. Chinook salmon go off the main stem to spawn in streams that they’re genetically adapted to, all the way down to Teslin and beyond, he said.
Year over year increases are good — but good is a fraught term when it comes to the dire situation Chinook salmon are in, Zimmerman said.
“One good year doesn’t mean a rebuilt run.”
Zimmermann referred to the concept of a shifting baseline. While year-over-year averages may look better, comparisons to historical averages from 30 years ago tell a different story, he said.
“It’s a completely different number. It’s a fraction. They’re down at least 80 per cent, so that’s kind of the part that’s the scary part.”
However, Zimmerman said that there is still five years of the international Yukon River Chinook salmon fishing moratorium, where there is no direct Chinook fishing along the Yukon River in Alaska or Yukon (although he acknowledged that there is some incidental, accidental harvest of Chinook salmon in Alaska).
The moratorium’s target is 71,000 Canadian-origin Chinook salmon crossing the international border: the pre-season forecast for 2025 was 18,000, accounting for mortality en route.
“While it is a very gloomy picture, there are still some indications that there is hope,” Zimmermann said.
“The people that I work with, all of our various organizations, the First Nations, the harvesters themselves, we’re doing the best we can to make sure that we get every fish in the spawning ground and every egg in the gravel.”