Huge B.C. sockeye run could get bigger

Scientists are puzzling over why they didn't see the mammoth Fraser River sockeye run coming, while hinting that estimates could go even higher on Friday.

As vessels flock in droves to scoop up what's believed to be the largest run in nearly a century, estimated at about 25 million salmon, the question again surfaces about how much experts know or don't know about the West Coast fish's journey.

It's a 180-degree turnaround from last year, when sockeye stocks were so depleted the federal government called an inquiry.

"It's easy to say the [Department of Fisheries and Oceans] can't count fish," said Simon Fraser University fish biologist John Reynolds, noting criticism levelled at the government.

'It's like trying to forecast the weather.' Fish biologist John Reynolds

However, Reynolds said, fish predictions in Alaska and other parts of the U.S. show equally imprecise results.

"Nobody else does it any better," he said.

The Pacific Salmon Commission, an independent joint Canadian-U.S. body that advises the federal Fisheries Department, increased this season's stock assessments Tuesday after recent test catches suggested a banner year not seen since 1913.

Barry Rosenberger, area director for Oceans and Fisheries Canada, says the sensational numbers were unlikely but not entirely unexpected.

The government's scientific forecasting document for this year's stocks, which presents a probability range, shows somewhere between a 10- to 20-per-cent chance that 25 million fish would return. Peoplewho aren't involved in the industry frequently only look to the 50-per-cent estimate: seven to 11 million this year.

"That's where the disconnect is," said Rosenberger, adding that while the long-term planning document is usually released in November, it was only released in June because they modified their approach to modelling.

Another upgrade in the sockeye run size can be expected Friday, Rosenberger said.

Fish hard to follow

Sockeye live for about four years, hatching from gravel nests in some 200 tributaries throughout the Fraser River basin.

They spend about a year in a lake before beginning their spring migration out to sea. Two years later, they return to spawn in the grounds where they were born.

"Technically, it's extremely difficult to follow juvenile fish once they reach the ocean you just lose them," said Reynolds, who holds the Tom Buell chair in salmon conservation.

Trying topredict the size of the run sofar in advance"is like trying to forecast the weather, which does affect the fish, and everything else that can affect them many, many months in advance," Reynolds said.

Pre-season figures are far less accurate than in-season counts based on test fishing in places such as the Strait of Georgia and the Strait of Juan de Fuca, which are used by the government to set regulations around quotas and when the fishery opens.

"You can't fish off the forecast, you have to fish off the real in-season information," Rosenberger said, adding notices with updated predictions go out twice a week.

"People say, 'Well you got 30 million now, you should have been fishing weeks ago.' We didn't have 30 million weeks ago."

But scientists are finally tweaking calculations based on new variables, Reynolds said.

Change in mid-'90s

They've now recognized that starting about 15 years ago, something big changed in the relationship between how many fish leave and how many return.

Temperature of the seas, food sources and predators all of which could be related to climate change as well as human intervention are factors that could play a role, he said.

Rosenberger agreed scientific advancement is necessary.

Only abouta millionof the estimated 10 million sockeye that were supposed to appear in 2009 arrived, forcing the closure of commercial fisheries and aboriginal food fisheries for First Nations in the area.

A commission headed by B.C. Supreme Court Judge Bruce Cohenis expected to tackle the question of why when it starts hearing evidence during the public inquiry next month.