Millions of Salmon Disappear From Canadian River
Date: 14-Aug-09
Country: CANADA
Author: Rod Nickel
Millions of Salmon Disappear From Canadian River Photo: Andy Clark
A sockeye salmon scurries through shallow water in the
Adams River while preparing to spawn near Chase, British Columbia
northeast of Vancouver.
Photo: Andy Clark
WINNIPEG, Manitoba - Millions of sockeye salmon have disappeared
mysteriously from a river on Canada's Pacific Coast that was once known
as the world's most fertile spawning ground for sockeye.
Up to 10.6 million bright-red sockeye salmon were expected to return to
spawn this summer on the Fraser River, which empties into the Pacific
ocean near Vancouver, British Columbia. The latest estimates say fewer
than 1 million have returned.
The Canadian government has closed the river to commercial and
recreational sockeye fishing for the third straight year, hitting the
livelihood of nearby Indian reserves.
"It's quite the shocking drop," said Stan Proboszcz, fisheries biologist
at the Watershed Watch Salmon Society. "No one's exactly sure what
happened to these fish."
Salmon are born in fresh water before migrating to oceans to feed. They
return as adults to the same rivers to spawn.
Several theories have been put forward to try to explain the sockeye's
disappearance:
* Climate change may have reduced food supply for salmon in the ocean.
* The commercial fish farms that the young Fraser River salmon pass en
route to the ocean may have infected them with sea lice, a marine
parasite.
* The rising temperature of the river may have weakened the fish.
The Canadian government doesn't know what's killing the fish, but
believes the sockeye are dying off in the ocean, not in fresh water,
based on healthy out-migrations, said Jeff Grout, regional resource
manager of salmon for the Department of Fisheries and Oceans.
It's too soon to know yet how widespread salmon losses are in the
Pacific salmon fishery, but British Columbia's northern Skeena River has
also seen lower-than-expected returns this year, Grout said.
Signs are more positive for other salmon species such as chinook, pink
and coho, he said.
The reduced salmon return affects the environment around the Fraser
River, Proboszcz said. After spawning, adult salmon die, creating a food
source for bears and eagles and adding nutrients for plants.
Food companies that rely on the Fraser for some of their salmon supply
will have to look to other areas of British Columbia or Alaska, Grout
said.
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