Salmon column misrepresents facts
By Grant Warkentin, Times Colonist January 25, 2011 9:00 PM
Columnist D.C. Reid's attempt to use the Pacific Salmon Commission's research report from last August to raise, as he calls it, a "nightmare scenario," is baseless fear-mongering (Jan. 20).
While Reid would like to blame the 2009 Fraser sockeye decline on viruses or pathogens from salmon farms and paint a word picture of a ridiculous doomsday scenario in which people eating Fraser sockeye salmon get infected with a mysterious virus, the science by the PSC and Kristina Miller says no such thing.
In fact, although Miller's study showed the salmon she studied had genetic links with "genes associated with leukemia," presumably the source for Reid's hysteria over "salmon leukemia," her very next sentence urges caution.
"This correlative data set cannot be used to assign cause to the association between a pre-existing signature and subsequent mortality," it says.
Simply put, correlation does not equal causation.
Reid also misrepresents the conclusions of the PSC report, which says scientists need to consider all options and do more research before they can draw any conclusions about why the 2009 Fraser sockeye run was so low.
More research is needed on wild salmon. Salmon farmers welcome the research, and the scrutiny that will come along with it. We are confident that our industry meets the highest standards when it comes to protecting our environment and that salmon farms and wild salmon can co-exist in B.C.
Grant Warkentin
Communications officer
Mainstream Canada
Grant Warkentin is responding to the following article:
Cohen Commission Told Fish Farms Likely Contributed to Sockeye Decline!
From the Times-Colonist - Jan 20, 2011
by D.C. Reid
Two weeks ago I summarized what scientists think are the main questions to investigate in the 2009 Fraser River sockeye collapse. Sixty-eight experts and observers did a heavy dose of considering and submitted their report to the Cohen Commission. They have contributed testimony to the evidentiary hearings, too, and this column tells you what they said, and other factors.
Among nine hypotheses, they crunched the available science from the early 1980s up to 2010 and each participant opined which he/she thought were likely causes. They found that where the fry were hatched and resided for two years and then swam all the way down the Fraser River were unlikely to have produced the massive kill. In 2007, for instance, the Georgia Strait sockeye seine found only 157 fry from the huge Chilko River area cohort of 139 million fry that started out. And, surprisingly, millions of fry, particularly the Harrison, take up residence in the Fraser plume, and so its entire Lower Mainland contaminants don't kill sockeye.
In the ocean, it turns out that it is unlikely that marine mammals ate them all, even though they snack on chum at the Puntledge River estuary. Nor did unauthorized fishing outside our 320-kilometre territorial waters account for losses. Later, up-river migration of adults -- as much as 600 kilometres -- seems not to have killed many returning adults either, nor affected the health of the next year's fry they spawned.
So what did they find? The most likely causes are: marine and freshwater pathogens like viruses, bacteria and sea lice; ocean conditions and a huge negative algal bloom inside Georgia Strait; outside waters were ruled out for 2007-2009. Georgia Strait conditions of algae, oxygen, salinity, acidity or other physical and biological conditions are seen to have long-term negative effects on survivability, though these conditions are not prevalent every year. And this may help explain the 2010 bumper crop that no one expected; and why Harrison River sockeye that transit Juan de Fuca have been growing in numbers steadily for the past 20 years, contrary to the trend.
Though the scientists thought pathogens were a big negative factor, more science is needed to absolutely nail these down. But it seems to be -- wait for it -- fish farm issues, say, sea lice, and viruses. Environmentalist Alexandra Morton has asked the commission to compel the farms to release data that they have been withholding. It is the virus situation that is the nightmare scenario: farmed Chinook salmon likely passed a salmon leukemia retrovirus to the farmed Atlantics and they infected the returning sockeye adults. This is DFO research from Dr. Kristina Miller. The sockeye managed the long swim upstream only to die prior to spawning.
Another scientist, Michael Kent, studying viral transmission, reviewed work that has shown this fast mutating bug can infect dogs, sheep and humans. This is the nightmare. Make sure you cook your Fraser sockeye well, and send a letter to Gail Shea saying: fund more of Miller's research, toute de suite
This is a fascinating, heavy crunching science report. If you read only one table in your investigation of this issue, let it be E-2. This table summarizes all the research for or against a possible explanation and will inform your understanding of salmon science for the rest of your fishing days: www.psc.org/pubs/FraserSockeyeDeclineWorkshopReport.pdf.
Read article at TimesColonist.com
