Salmon virus issues linger in B.C.
A week and a half ago, waves were made by anti-salmon farming crusaders about a “new” virus found in samples of farmed salmon purchased from a number of grocery stores in B.C. Allegations were made that this virus could have something to do with the often fluctuating stocks of returning wild salmon to rivers in B.C. The critics of salmon farming contend that this virus- a piscine reovirus (PRV) previously also found in Norwegian salmon farms- is the causative agent of a disease named Heart and Skeletal Muscle Inflammation (HSMI), despite no apparent scientific evidence that this is the case. The “Salmon Farm Science” blog posted the following information earlier this week;
We see someone managed to get a hold of the lab report for Ms. Alexandra Morton’s farmed fish samples last week and posted it. We snagged it and have re-hosted it for your viewing and educational enjoyment. Yes, we finally found it, despite asking Ms. Morton for it several times in email and being ignored; and also asking for it in comments on her blog (from which we have now been blocked simply for asking her to prove her claims). But we got it anyway.
And this lab report is important, because it shoots holes in Ms. Morton’s claims about PRV (piscine reovirus) and HSMI (Heart and Skeletal Muscle Inflammation), which she stated are present in farmed salmon. Important, because she has read it, and must know she is playing fast and loose with the facts.
Her words:
Test results report 44 out of 45 farm salmon purchased from the Superstore and T&T markets throughout Vancouver tested positive for a newly identified Norwegian virus. The piscine reovirus weakens the fish’s heart causing Heart and Skeletal Muscle Inflammation (HSMI).
She also stated:
Our discovery of the salmon heart virus, piscine reovirus (PRV) which causes Heart and Skeletal Muscle Inflammation (HSMI) has been reported on in the press.
What the lab report actually says:
“The PRV sequences detected by RT-PCR could be from viable or non-viable virus.”
“The presence of PRV sequences in the tissue samples does not imply that the subject fish had HSMI or that HSMI is present in the area where the subject fish were collected from.”
“Confirmation of PRV infection requires further investigation.”
“The laboratory did not participate in the collection of the samples or in the custody of the samples prior to receipt of the samples. The laboratory therefore cannot guarantee the integrity of the sample.”
The lab report stated the virus detected in PCR testing was 99 per cent identical to two Norwegian strains; however, the lab report also points out those two Norwegian strains are the only PRV sequences in the internationally-used genetics database. The virus looks like the ones on file, but there are only two strains on file. That’s kind of like trying to match fingerprints in a database of two. We really have a lot to learn about fish viruses, and this lab report shows that we can’t make broad claims based on a little bit of data. But that doesn’t fit in with the anti-salmon farming activists’ modus operandi of “exaggerate to apocalyptic proportions,” now, does it?
