Fraser sockeye returns lowest in 50 years
Summer's run falls 60 per cent below the average, fisheries department says
Scott Simpson
Vancouver Sun
Tuesday, September 09, 2008
Fraser River sockeye returns appear to be at their lowest ebb in 50 years, Fisheries and Oceans Canada said Monday. This summer's returns are already the lowest in the four-year cycle of migrating Fraser-system sockeye, with an average return since 1958 of 4.4 million of the prized salmon on this cycle.
This year is 60 per cent below that amount -- 1.7 million fish -- fisheries department's salmon team leader, Paul Ryall, said in a telephone interview.
The parent group for this year's return, which migrated into the Fraser system and spawned in 2004, was similarly weak at about 1.9 million fish.
Other than a brief opening for commercial and recreational fishermen in July, and some catch by U.S. fishermen under the Pacific Salmon Treaty, the only appreciable fishing has been by first nations for food, societal and ceremonial purposes.
The commercial and sport fisheries were authorized when a brief July bump in migration created an impression that a major run had arrived off the southern coast of Vancouver Island.
But when it became evident that the run was in fact exceptionally weak, the department quickly shut the fishery down.
"It became clear that the fish just weren't there, and we closed any further commercial opportunities," Ryall said.
The department warned as long ago as December 2007 that this year's run would be exceptionally weak, based on a low number of fish -- 521,000 -- that made it back to spawning grounds four years ago to birth this year's run.
Poor marine survival is also considered a key factor for the continuing struggles of the species -- the survival rate for young salmon to mature to adulthood and return to spawn can run to five per cent, or even higher in a year in which the ocean is a lush, nourishing environment.
Ryall said the department estimates this year's run had a survival rate of only about one per cent from the time they hatched and migrated down to the ocean, to the time they made their way back to the river as adults.
It's not entirely clear what's causing the survival problem -- everything from climate change and shifting ocean currents to ocean acidification have been considered potential culprits.
What is certain is that both Alaskan and Russian sockeye populations are thriving even as B.C.'s struggle, and that Fraser sockeye also continue to exhibit unanticipated migratory behavior -- moving out of the ocean and into the Fraser River about five days earlier than usual.
There is a bit of good news in this -- for the fish, if not for the people who like to eat them.
In anticipating this year's weak run, the department consulted over a period of months with first nations living along the sockeye's migration area in the Strait of Georgia and Johnstone Strait, as well as aboriginals living along the Fraser itself, and commercial and sport groups -- bracing them in advance for a bad year.
In a typical year, first nations take 800,000 to one million sockeye out of the Fraser, but this year the department limited their fishing and they've only caught 400,000. As a consequence, the expected number of fish that will escape human predation and make it back to spawning grounds is about 1.2 million.
That's an improvement over the 50-year average escapement of 822,000.
ssimpson@vancouversun.comTHE ONES THAT GOT AWAY
The Fraser River sockeye fishery this year was one of the worst on record.
This year: Total return 1.7 million
Average number of sockeye returning each summer on the current (2004-2008) cycle: 4.4 million
HOW THE NUMBERS WORK
Of the 1.7 million Fraser sockeye total return this summer:
online
You can comment on this story at vancouversun.com/usaid
© The Vancouver Sun 2008
Author
Topic: Fraser sockeye returns lowest in 50 years (Read 19041 times)