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Early count points to steady chinook salmon numbers in Yukon River

The first data is starting to come in assessing the strength of this year's Yukon River chinook salmon run — and so far the numbers are promising, says a U.S. biologist.

Record-breaking warm water in Yukon River could have an effect, say biologists

An underwater camera at the Whitehorse fish ladder and hatchery captures chinook salmon travelling by. The Yukon chinook salmon run has slightly increased in in recent years, but the trend has not been in a straight line. (Yukon Energy)

The first data is starting to come in on the strength of this year's Yukon River chinook salmon run — and so far the numbers are promising, says a U.S. biologist.

"Things can change, because we're only at the first quartile, but it's looking good," said Holly Carroll, area management biologist with Alaska's Department of Fish & Game.

Carroll says the numbers this year are looking similar to last year.

The Yukon chinook salmon run has slightly increased in in recent years. But the trend has not been in a straight line.

The growth has been frustratingly slow for people who are going without fish, and the chinook numbers are still far short of levels seen in the 1990s.

Every year, the fish migrate more than 1,000 kilometres as adult fish to return from the Bering Sea into Alaska, then swim upriver to spawning grounds in Yukon.

A chart shown at an April 2019 Whitehorse meeting of the Yukon River Panel illustrates historic runs of Yukon River chinook salmon. (Philippe Morin/CBC)

So far this year, about a quarter of the run has passed an underwater sonar at Pilot Station in Alaska, which helps scientists count. 

The salmon passage at this time is estimated to be 28,612 fish. The historical cumulative average is 41,442 fish.

Warm water could affect fish

One thing being watched this year is water temperature — the Yukon River has been breaking records.

Carroll says measurements from the Alaska Department of Fish & Game show water temperatures reaching 15 C, while the average maximum is usually 12 C. 

Those measurements don't account for the entire river, as they're based on measurements near the coast. However, Carroll says it is enough to cause concern. 

"We are seeing record-warm water temperatures down here, so I do think that's going to be harder on the fish," Carroll said.

Chinook salmon fry being released into Yukon's Fox Creek, as part of the Ta'an Kwach'an Council's restocking program. (Jane Sponagle/CBC)

The issue was discussed on Tuesday during what's called an in-season salmon management teleconference, hosted by the Yukon River Drainage Fisheries Association.

During the call, people in different Alaska communities shared what they were seeing on the Yukon River — and some reported fish with disease. 

Basil Larson, a biologist from Russian Mission, Alaska, said one local resident found two chinook salmon with a "severe" parasitic infection.

A similar thing was reported in Anvik, Alaska. 

Some in the teleconference also suggested warmer water may be causing fish to spoil faster. 

"People complain about the fish 'cooking in the net,' because they get soft when they're left there a while," said Howard Beasley from Galena, Alaska.

Wayne Jenkins, executive director of the Yukon River Drainage Fisheries Association, told callers that "it feels like we're into climate change pretty deeply all over the place," and noted that warm temperatures do make fish more susceptible to disease. 

However, Carroll cautioned against drawing conclusions, saying that anecdotes in such small numbers aren't necessarily signs of a trend. 

Chum decline

Another species of salmon is proving potentially more worrisome. 

Carroll says numbers for chum salmon counted at Pilot Station are "well-below" average so far.

The summer chum salmon passage is estimated to be 13,741 fish, which is only a fraction of the historical cumulative median of 155,521 fish. 

Carroll says chum numbers can swing wildly from year to year.

While it is too early to say if this trend will sustain all season, "it does indicate a weak or a late run for chum," she said.

Chum is a staple of commercial fishing in Alaska, which may have to be delayed this year. 

Debate about harvest numbers

The chinook numbers have proved frustrating to Indigenous leaders in Yukon, some of whom have called for the U.S. to harvest fewer fish.

A salmon fisherman on the Yukon River in Alaska, in 2001. (Sam Harrell/Fairbanks Daily News-Miner/File/Associated Press)

The chinook fishery in Alaska and Yukon has been under restrictions for years. However, about 12,000 Alaskan subsistence fishers and 4,000 Indigenous people in Canada retain rights to fish.

Indigenous groups such as the Teslin Tlingit Council in Yukon have placed voluntary bans on fishing for years. 

On the Tuesday teleconference, Vuntut Gwitchin First Nation member Stanley Njootli, Sr. from Old Crow, Yukon, said they would love to fish for chinook, but would first wait to see what's coming their way. 

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