The chinook salmon migration is underway and it's off to a good start.  

Sonar equipment at the mouth of the Yukon River near the Bering Sea counts the number of fish passing through. So far, four groups or "pulses" have started the upriver migration. 

"It's looking really good," says Shawn Larson, fish biologist with the Alaska Department of Fish and Game.

Larson says more than 253,000 chinook have been counted. He says that's higher than the average of 208,000 for this time of year, and also exceeds the pre-season forecast.

He credits Alaska and Yukon fishers for their conservation efforts designed to increase salmon populations.

"It's been incredibly hard for subsistence users all up and down the river," he says. "They rely on these fish very significantly." 

Larson also thinks more favourable ocean conditions could be bolstering numbers. 

1st chinook salmon have crossed the border

Some of the salmon entering the river will make it the 2,000 or so kilometres upstream to the Yukon border and into smaller tributaries and lakes for spawning.  

Data from the sonar station at Eagle, Alaska, immediately downstream of the Canadian border, shows that the majority of the chinook are now starting to cross into the Yukon. 

Based on the numbers so far, Larson says it's likely the upper reach of this year's escapement goal will be met. Escapement measures the number of salmon that make it to spawning grounds. The goal for this year was set at 42,500 to 55,000 by the Yukon River Panel, the body that represents interest groups on both sides of the border. 

According to the panel, Yukon River salmon spend their first year of life in fresh water before migrating to the Bering Sea. They return to the spawning grounds after up to six years in the ocean. 

First Nations, governments and industry on both sides of the border have been working to increase salmon returns since the Yukon River Salmon Agreement was signed in 2001. 

With files from Leonard Linklater