FAIRBANKS — The Yukon River is having strong runs of silver and chum salmon this fall, giving a boost to fishermen after another tepid summer for king salmon.

Sonar counts on the Lower Yukon at Pilot Station had tallied 233,000 silver salmon by Sept. 3, far above the historical median of 126,600 by that date. At that pace, more than 245,000 silvers are expected on the Yukon this summer.

Jeff Estensen, an area management biologist with the Alaska Department of Fish and Game, said it should be the strongest run of silvers in at least four years, allowing for commercial and subsistence openings last week on the lower Yukon. Last year, only about 80,000 silvers passed the sonar at Pilot Station.

It’s also been a good year for fall chum salmon, with about 800,000 fish tallied, roughly 100,000 more than during a typical even-year run. The mid-summer chum run sent 1.9 million more fish down the Yukon.

Those solid numbers have helped offset a weak run of king salmon this year, which left the fishery closed to subsistence users. More than 60,000 kings reached the Canada border, which met a treaty obligation for just the second time in five years, but Alaska fisheries on the Yukon were halted to achieve it.

Estensen said other salmon species may help ease those closures.

“Especially with the (shortage of) kings, we’ve been fortunate to have good runs of chums to give those subsistence users something,” Estensen said.

The fall chum run is healthy enough that there shouldn’t be a problem meeting treaty obligations on that species. A range of 72,000 to 104,000 fall chums need to make it to the border, along with a percentage of fish caught in U.S. waters.

Estensen said he doesn’t anticipate a problem reaching those targets.