The number of Yukon River chinook that made it to spawning beds along the mainstem of the Yukon last summer just missed the minimum target, says the international report released recently.

Scientists estimate 42,052 chinook reached their spawning grounds, not including Porcupine River chinook.

It was the lowest spawning escapement since 2013, according to the report produced every spring by the Joint Technical Committee of the international Yukon River Panel, which is in charge of managing all salmon stocks in the Yukon River.

In 2018, by comparison, the spawning estimate was 54,474, and the five-year average to 2018 is 67,518.

In 2015, it’s estimated 82,674 chinook spawned along the mainstream, which includes tributaries like the Pelly and Stewart rivers. It was the largest escapement estimate going back to 1982.

The total harvest of chinook in Alaska and Yukon was 54,873, with Alaskans taking 51,733 and the Yukon aboriginal subsistence fishery harvesting 3,104 – 2,764 on the mainstem and 340 by Old Crow residents on the Porcupine River.

The failure to meet the minimum escapement goal on the Yukon side of the border occurred even though the total number of chinook passing the Pilot Station sonar upriver from the mouth was estimated at 219,624. It was the second largest estimate at Pilot Station going back to 2006.

The Yukon River chinook stock has been in trouble for several years. There was once a time when the total harvest of chinook on both sides of the border would approach or exceed 200,000 chinook.

There have been no commercial fisheries on either side of the border for several years, though Alaska’s harvest in 2019 did include 3,110 chinook caught by commercial boats targeting other salmon runs like the run of summer chum salmon.

The subsistence fisheries on both sides of the border have been exercising conservation for several years to assist with rebuilding the chinook stock.

In 2014, for instance, the Yukon fishery harvested just 103 chinook largely for ceremonial purposes while the Alaska fishery took just 3,287, or a fraction of what it normally would take.

The annual subsistence harvest, however, has been increasing in recent years.

The 2019 subsistence harvest in Alaska is estimated at 48,379, the largest since 2007 and well above the five-year average to 2018 of 20,480.

The estimated harvest by Yukon’s subsistence fishery in 2019 of 3,104 was in keeping with harvest levels in recent years but well above the five-year average of 2,196. which includes the record low harvest of 103 chinook in 2014.

Steve Smith of the federal Department of Fisheries and Oceans in Whitehorse explained the 2019 pre-season estimate predicted a return of between 66,000 and 99,000 chinook of Canadian origin.

Given the estimated harvest of Canadian chinook by Alaska and the number of chinook that passed by the Eagle sonar just upriver from the Yukon-Alaska border, the anticipated return was at the low end, he explained.

The manager of treaties and fisheries for the Yukon River said there are a handful of factors that could explain a return at the low end of the forecast, including chinook mortality during the migration.

Temperatures last summer were warm, and there was low water in the Yukon River, both of which could have caused increased mortality, he said.

Smith explained the annual spring meeting of the Yukon River Panel did not occur because of the COVID-19 crisis, though the Canadian and U.S. co-chairs of the panel did issue a joint statement regarding the 2020 forecast.

The panel is forecasting a return of Canadian origin chinook this summer between 59,000 and 90,000, or lower than the forecast for 2019.

The report notes the 2019 return of 99,000 fall chum to the Yukon did meet the minimum spawning escapement goal.

But the total Canadian harvest of 3,759 on the mainstem of the Yukon River and Porcupine River was the lowest since 2009 and well below the five-year average of 5,157.

Of the total Canadian harvest, 1,728 fall chum were taken by the commercial fishery and 1,031 were taken by the aboriginal food fishery.

The total harvest estimate for fall chum in Alaska last year was at 332,905, with the commercial boats harvesting 268,360 and the subsistence fishery taking 63,862.