Chinook-rich Yukon fishers can thank a sonar glitch for their good fortunes.
Alaska regulators “underestimated” the Yukon River chinook run, causing them to slap unprecedented restrictions on Alaskan subsistence fishers.
As a result, tens of thousands more salmon have crossed the Canadian border than initially predicted.
“Double” the expected number of chinook salmon were counted at the sonar station at Eagle, Alaska—just before the Canadian border, said Russ Holder, Yukon area in-season manager for the US Fish and Wildlife Service.
The extra salmon were greeted with jubilation in the Yukon.
Canadian fishery regulators were able to lift all restrictions on Yukon First Nations, and even allowed a brief commercial and domestic harvest.
It was the first time in three years that Alaska had let enough chinook over the border to satisfy their needs.
But in Alaska, regulators began to realize that something had gone horribly wrong.
“You go, ‘Well, wait a minute. How did more fish make it upriver than were counted down below?” said Holder.
In June, sonar equipment at Pilot Station – just 197 kilometres from the mouth of the Yukon River – was indicating one of the river’s worst-ever runs of chinook salmon.
The run was still bad, but not nearly as bad as the sonar had led regulators to believe.
The misread was due to high water levels, say fishery officials.
A particularly heavy snow season rendered the Yukon River swollen and cloudy by the time salmon started making their way upstream.
“It is much more difficult to penetrate through the water with all that material in there,” said Holder.
At Eagle, the river is half as wide as at Pilot Station, and silt levels are much lower – allowing a more accurate reading of salmon numbers.
“It’s just a much better location to get a much more accurate number of fish that are passing,” said Holder.
If not for the sonar equipment at Eagle, the glitch would never have been detected.
Eagle didn’t have sonar equipment before 2004. Past glitches at Pilot Station could easily have passed undetected.
“Very possibly, and very likely,” said Holder.
Alaska fishers balked at the early summer restrictions.
Now, they are livid.
“Terrible. Horrible. There’s no word that explains my frustration,” said Tim Andrew, natural resources director for the Alaska-based Association of Village Council Presidents to the Anchorage Daily News.
A poor salmon harvest in 2008 led to a humanitarian crisis in Yukon River villages last winter.
With an even-lower salmon harvest for 2009, Alaska villagers are bracing for the worst.
“We suspect that satisfying a treaty won’t buy any heating oil or food this winter,” read a post on the Alaska Dispatch blog.
Many fishers were hoping to fill their smokehouses with chum salmon from the fall run.
But Pilot Station’s sonar counters are now indicating a record-low run of chum salmon – prompting a new wave of fishing restrictions.
This time, the sonar is on the mark, said Holder.
“The fall chum estimate at Pilot is typically much closer to reality than what often can happen in the spring,” he said.
With lower water levels and less debris, the chances are much lower that equipment is being affected.
Contact Tristin Hopper at