From the Vancouver Sun – Jan 13, 2011

by Margaret Munro

Volcanic eruptions, giant squid and sea lice have all been invoked to
explain the wild swings in one of Canada’s most valuable fisheries.

Now
scientists have raised the spectre of a mysterious virus killing huge
numbers of Pacific salmon before they reach their spawning grounds.

“The
mortality-related signature reflects a viral infection,” a team of
federal and university researchers reported Thursday in a study into the
collapse of British Columbia’s famed Fraser River sockeye runs.

The
compromised salmon that appeared to have a viral infection at sea — a
phenomenon co-author Scott Hinch at the University of British Columbia
describes as “dead fish swimming” — were 13.5 times more likely to die
before spawning than healthy fish.

The study, published
Thursday in the journal Science, does not identify a microbial culprit,
but suggests the virus may be associated with leukemia and lymphoma.

“There is no doubt there is some form of pathogen involved,” Hinch said.