A spawning chinook salmon. (California Department of Fish and Wildlife/Wikimedia Commons)

A spawning chinook salmon. (California Department of Fish and Wildlife/Wikimedia Commons)

Chinook salmon return begins in Whitehorse

Ten fish pass dam as threatened salmon near the end of their spawning migration

The chinook salmon have begun their return to the upper reaches of the Yukon River system. How many of them will arrive this season remains an open question unlikely to have an encouraging answer.

The first chinook of the season passed the Whitehorse dam fish ladder on July 31 heading on to the final leg of the world’s longest salmon migration. By Aug. 8, 10 fish had passed the ladder. Last year, 164 fish were counted at the ladder with the first fish passing through on Aug. 2 and the rest following over the next month.

Predictions issued by the Department of Fisheries and Oceans (DFO) as early as mid-July suggested it was unlikely that the number of returning fish would achieve spawning objectives or allow for any harvest of the fish along the river. Per a DFO bulletin, the management objective for the Canadian-origin chinook is a return of 50,000 fish.

Among those observing the salmon in the Yukon River and weighing in on decisions about their management is Sebastian Jones. Jones sits on the Yukon Fish and Wildlife Management Board as well as the Yukon Salmon Subcommittee which was created as part of the Umbrella Final Agreement in order to be the main instrument for managing salmon in the territory.

“We were prepared to make that call pretty early. The indicators, you know, right from last year were showing us that it was pretty likely that there was going to be another bad year. So, we started to prepare ourselves and our partners for a year without fishing a long time ago,” Jones said of the closure of fishing along the river.

Considerations that go into making management decisions beyond the number of returning fish include: how many fish are being caught in other fisheries, environmental conditions such as river levels and the prevalence of any diseases that might affect the fitness of the fish stocks.

Jones said weather is even a greater concern than disease when it comes to the health of the fish.

“We’ve had a smoking hot July that has really boosted river temperatures and this has a real effect on salmon migration.”

Jones explained that this is because warmer water speeds up the fish’s metabolism causing them to use more calories and oxygen. Because the salmon don’t feed and replenish their energy reserves once they begin their freshwater migrations and because warmer water contains less dissolved oxygen, the salmon’s ability to survive and spawn is compromised under these conditions.

“When the water gets too warm, usually around 21 degrees, salmon can actually just keel over. There are some rivers in the Yukon where the temperature has been up to 20 degrees,” Jones said.

Conclusions about mortality can’t be drawn yet but Jones said the counts coming out of the sonar station at Eagle, Alaska are slightly better than what was observed last year. However, the count is still much lower than what would be considered normal. Jones said a “normal” year hasn’t been observed since serious declines in the salmon stocks began in the late 1990s.

According to Jones, the cause was simple: too many people catching too many fish and targeting the largest and healthiest of the salmon for too long.

Other than closing the harvest along the river, Jones said all that can be done is protecting the environment, both local river habitat and the wider climate. He said it is important to take steps to stop the compromising of water levels and quality by human activity.

“Along the Yukon River, we are approaching a consensus that we need to manage fishing much better than we have in the past, but out in the ocean we’re still a long way from doing that,” Jones said.

“We really have industrial level alterations to the high seas, to the oceans, to the point where what we do in the river no longer matters as much.”

Although harvest outside territorial waters is outside its control, Jones said Canada is slowly moving in the right direction. Canada has pledged to protect 30 per cent of its marine and coastal areas by 2030.

Jones also acknowledged the feelings of despair caused by the shrinking salmon returns especially for Indigenous people whose culture has depended on the annual return of the fish for tens of thousands of years.

Contact Jim Elliot at jim.elliot@yukon-news.com