Friday, January 14, 2011

Researchers Find Viral Infection Killing Fraser Sockeye

Over the past two decades elevated in river temperatures have led to high prespawn mortality in Fraser sockeye salmon. Compounding the problem is the fact that despite warm water temperatures, the sockeye which would normally stage off the river mouth, were instead entering the river as much as a month earlier than normal. The result has been catastrophic prespawn mortality, in excess of 95% for some run years. Fish simply die on their way to their natal river or on the spawning gronuds prior to successfully spawning. Now a group of Canadian researchers has publised findings from a four year study into prespawn mortality on the Fraser and their findings are raising concern about the well being of Fraser River sockeye. The group found genomic evidence of a widespread viral infection in Fraser River sockeye and that pre-spawn mortality rates increased 13.5 fold in infected fish. The story is still evolving and more research will be required to fully uncover the magnitude and scope of the disease, however many in BC are concerned that open containment fish farms in the migration route of Fraser sockeye are the source of the virus. Up to now fish farming companies have refused to release disease records but a recent decision by the Justice Bruce Cohen mandated the release of all disease records for the last 10 years. More information in the Vancouver Sun website:

Alex Morton's Blog:

1 comment:

Anonymous said...

Leaked 2009 briefing notes obtained by FOI from deputy minister to minister DFO indicate the possibility of viral infection.