Chum, chinook returns fall short across Yukon, Western Alaska
Poor chum and coho returns led to some of the lowest commercial harvests in decades across much of Western Alaska and biologists are unsure why far fewer Yukon chinook are making it to Canada in recent years.
The Yukon River summer chum return of approximately 733,000 fish was sufficient to meet the minimum escapement goal for the entirety of the massive drainage but it did not allow for a significant commercial fishery and was far less than expectations.
Fishing was closed through the first half of the run while it was unclear if a harvestable surplus of chum would be available according to the Alaska Department of Fish and Game’s preliminary Yukon River summer fishery summary.
Commercial fishermen, primarily in the lower Yukon, harvested just 13,968 chums in the summer fishery, which was 97 percent less than the five-year average of nearly 449,000 fish.
The minimal catch translated to a total-fishery ex-vessel value of just $51,440 in 2020 for a fishery that typically generates roughly $1.5 million, though prices of 60 cents per pound for lower Yukon chum and 29 cents per pound were in line with previous years.
Prices in some other salmon fisheries were low — particularly early in the season — as the pandemic slowed restaurant demand for fish.
Managers had predicted a rather average return of about 1.9 million summer chum, which would have left a harvestable surplus of about 1.1 million fish, according to ADFG. The summer fishery comprises chinook and chum that enter the river generally before July 15, at which point management in the lower Yukon transitions to the fall chum and coho runs.
The chinook return of an estimated 161,859 fish to the Pilot Station sonar was less than last year when 219,624 chinook reached the lower Yukon, but was in line with the expected return.
However, an unusually small portion of the fish passed the sonar at Eagle near the Canadian border. Managers estimated 77,000 of the chinook were of Canadian origin based on in-season run assessments, yet just 33,005 fish were counted at Eagle, according to the summary. The minimum escapement goal for passage beyond Eagle is 42,500 chinook, which also does not provide for harvest in Canada per the Pacific Salmon Treaty.
Managers speculated that near record-high water levels in the Yukon from a deep snowpack possibly fatigued fish that otherwise would have reached Eagle. They also documented reports of high rates of Ichthyophonus, a parasite, in salmon caught in the upper river, which could have increased mortality.
On the bright side, the chinook sampled by ADFG biologists at Eagle were older and more of them were female than in recent years. Age-6 chinook comprised 53 percent of the sampled fish — above the 10-year average — and 3 percent were age-7 salmon. Females comprised 54 percent of the sampled fish, compared to 44 percent over the past decade, according to department data.
Biologists have documented a general decrease in the size of chinooks across their range in recent years, largely because more of the fish are returning at age-4 or age-5. The smaller salmon are less likely to spawn successfully and smaller females carry fewer eggs, which also reduces the odds of offspring.
To the north, low commercial catches in July and concerns from subsistence harvesters about poor chum catches along the Kobuk River caused Kotzebue-area managers to cut commercial fishing time from 60 hours per week in July to as little as 24 hours per week in early August.
The harvest of 149,808 chums was the lowest in the Kotzebue District set net fishery since 2007 and netted $542,308 in ex-vessel value, according to ADFG figures. The fishery has a long-term average harvest of approximately 230,000 chum but it produced a catches of greater than 400,000 fish from 2016-2019. Kotzebue chum sold for an average of 45 cents per pound this year, which was up from 39 cents a year ago.
In addition to also having their smallest chum harvest since 2008, Norton Sound fishermen dealt with a very small coho return. The poor showings from the primary species targeted in the district led to a catch of 50,679 salmon in all, which was just 15 percent of the 10-year average harvest, according to the Norton Sound season summary.
The cumulative ex-vessel value of $290,302 for the five-species harvest was just 12 percent of the five-year average. The Norton Sound catch generated approximately $2.1 million last year and more than $4 million in 2018.
The Norton Sound pink salmon run was — as it has been of late — a near-record return. However, processors shied away from purchasing them, according to ADFG managers, resulting in a catch of 6,950 pinks. That was down from a harvest of more than 75,000 a year ago.
The 2020 Norton Sound coho harvest of 14,650 fish was less than 10 percent of the five-year average and the 26,365-fish chum harvest was 17 percent of the five-year average of 151,442 salmon. Additionally, 906 Chinook and 1,808 sockeye were harvested from Norton Sound.
Elwood Brehmer can be reached at [email protected].