The number of sockeye salmon migrating from the Pacific Ocean up the Fraser River in B.C. has dropped off significantly this summer, mystifying the government body tasked with protecting the species.
The Pacific Salmon Commission, an organization formed by the Canadian and U.S. governments, said in a news release on Tuesday they now expect 600,000 sockeye to swim up the river this summer - less than a quarter of their previous estimate of 2.86 million.
Because of the low migration numbers, the commission said the fishing of sockeye by commercial fisheries on the Fraser River remains closed.
After a meeting last week, the public body released a statement saying sockeye are "currently tracking substantially below forecast" and are "exhibiting a protracted migration pattern" up the river.
While the sockeye's migration should be well underway by early August, the commission said only 173,000 of them have passed by the Mission counting station.
Higher than normal numbers were expected this year, making news of the sparse migration particularly worrying.
Almost nine million sockeye spawned in the Fraser River system in 2005, much more than usual. They migrated to sea in 2007, spurred by good "physical and biological indicators," the commission said, such as water temperature and food availability. That should have translated into a more abundant inward migration in 2009.
Instead, the commission said "most Fraser sockeye stocks have experienced much poorer than average survival," meaning many of them appear to have unexpectedly died in the ocean.
The reason for the population's apparent collapse "is presently unknown." But the commission noted that until recently, migration conditions in the Fraser River had been "adverse for the past two weeks due to the sustained period of hot, dry weather and low discharge levels," suggesting that B.C.'s unusual summer weather may be a factor.
Time will tell whether the collapse in migration numbers for sockeye will hold for other species of the fish such as pink salmon, which migrate upstream later in the season. The commission said it should have a clearer idea of how pink salmon returns are proceeding within two weeks.
It will also be investigating to find out why there have been such low returns this season.
For the past two years, commercial and recreational fishing has been banned on the Fraser River due to poor migration numbers. Last year, the U.S. government also cancelled commercial salmon fishing off the coast of California and Oregon.
There has been an ongoing debate about whether sea lice from industrial fish farms have been affecting the population of pacific wild salmon.
Ernie Crey, an Aboriginal fisheries manager, said that the industry has moved "from a crisis to a catastrophe."
He told CTV News Channel on Thursday that the sockeye run was the "bread and butter for the commercial and Aboriginal fisheries" and that the count could come in well below the 600,000 mark.
