By Margaret Munro Postmedia News
Volcanic eruptions, giant squid and sea lice have all been invoked to explain the wild swings in British Columbia’s famed Fraser River sockeye-salmon runs.
Now scientists are raising the possibility that a mysterious virus is responsible for 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 that tagged and tracked wild adult sockeye salmon, then biopsied their gill tissues.
The compromised salmon, which appeared to have a viral infection at sea — a phenomenon study co-author Scott Hinch at the University of B.C. describes as “dead fish swimming” — were 13.5 times more likely to die before spawning than healthy fish. Continue reading →