Marine Harvest fights back on disease allegations
The disease in question is called Heart and Skeletal Muscle Inflammation (HSMI). According to a peer reviewed paper published in Norway last year (Veterinary Research), the authors described the disease as “one example of an emerging disease in farmed Atlantic salmon (Salmo salar L). Since the first recognition as a disease entity in 1999 it has become a widespread and economically important disease in Norway. The disease was recently found to be associated with infection with a novel reovirus, piscine reovirus (PRV). The load of PRV, examined by RT-qPCR, correlated with severity of HSMI in naturally and experimentally infected salmon. Our results confirm the association between PRV and HSMI, and strengthen the hypothesis of PRV being the causative agent of HSMI”.
In British Columbia, the PRV virus has been found in both farmed and wild salmon, but no disease outbreak or loss of fish has ever been recorded. That’s why Marine Harvest fought back, rejecting allegations by environmentalists who claimed that the company had moved “diseased fish” from its hatcheries to seawater sites, issuing the following statement late last week;
Marine Harvest Canada has today come under attack by long time anti salmon farm campaigner Alexandra Morton with an Ecojustice led court action against the company and the Department of Fisheries and Oceans. Citing rumors of an apparently benign virus called piscine reovirus (PRV), the highly publicized filing of suit falsely alleges that the company has transferred diseased fish to its salmon sites. Limited testing for PRV in BC has found it to be present in some wild and farmed salmon but none of these farm-raised or wild salmon have been diagnosed with a disease.
Contrary to the opinions of Ms. Morton, DFO and CFIA do not consider PRV as a microbe of concern and it is not on the list of reportable diseases/pathogens. At the present time PRV appears to be a benign virus that may have been long present in the world's oceans. "Marine Harvest has the greatest respect for the ocean environment in which we grow our fish and we would not introduce fish that were carrying a disease" said Clare Backman, Sustainable Programs Director for Marine Harvest Canada. "Our fish are vaccinated against common disease causing agents before leaving the hatchery and we continue monitoring their health throughout their lifetime."
Marine Harvest Canada is very disappointed by Wednesday's court action which is lacking in substance and apparently designed for publicity purposes. Marine Harvest Canada is prepared to vigorously address these false accusations and to defend its good practices and excellent operations in BC.
While HSMI has never been found in B.C., one of the co-authors of the Norwegian study, Marie Løvoll of the Norwegian Veterinary Institute, told FishfarmingXpert that she “was strong in the belief that PRV is a causal agent of HSMI”, but that as with all other diseases, “other factors must contribute in order for an outbreak to occur”. And the B.C. Salmon Farmers Association referred to the study stating that “There has been no causal link between PRV and HSMI. (The paper) suggests that PRV is a cause of HSMI, but the paper notes specifically that the finding of PRV does not establish a HSMI diagnosis- and the paper’s conclusions are not uniformly accepted. While PRV has been found in B.C., HSMI has not.
