Disease in fish claimed wrong by salmon farmers
Fis, Tuesday, April 17, 2012
Salmon farmers and government officials are now together insisting that the claims by biologist Alexandra Morton about a newly identified virus in farmed salmon are wrong.
Mary Ellen Walling, BC Salmon Farmers Association (BCSFA) executive director, argued that the tests conducted on the salmon bought at supermarkets, and which found evidence of piscine reovirus (PRV) and then linked it to heart and skeletal muscle inflammation (HSMI), were unscientific and meant to sensationalize.
"The actions that returned these positive tests are highly unscientific and the information released alongside them is considerably speculative," Walling said.
"It's really unorthodox. We don't know where these fish came from or how they were treated. There's a huge opportunity for cross-contamination," she noted, Victoria Times Colonist reports.
Morton, a salmon advocate and vociferous opponent of open-net pen salmon farming, said she obtained fish from a supermarket because she lacks access to farm fish for testing.
"I challenge them to let me test their fish," she said.
Morton obtained salmon from Superstore and T&T markets in Vancouver last February and sent the samples to the Atlantic Veterinary College in Prince Edward Island (PEI) and a Norway laboratory; both labs determined that piscine reovirus was present in 44 out of 45 fish. Staff at the grocery stores told Morton the fish was sourced from BC salmon farms.
Morton then noted that the most recent scientific studies show the virus causes HSMI, but others insist this remains unproven.
"Some scientists feel there is an association between PRV and HSMI, but that opinion is not uniformly held," Walling explained. "In BC, the government fish health lab assesses heart muscles routinely for indications of disease and has not found any consistency between these tissues and the presence of this virus."
She stressed that HSMI has never been found in BC farmed salmon.
Department of Fisheries and Oceans Spokesperson Frank Stanek said the link between PRV and HSMI is unverified.
"Government of Canada scientists have not confirmed the presence of this virus in Canadian fish, despite extensive monitoring and testing," he said.
But Morton contends that some of the fish tested showed a classic symptom of HSMI: they were grossly undersized.
Conversely, Gary Marty, BC provincial fish pathologist, said the fact that Morton found most supermarket farmed salmon have PRV proves the virus is not causing disease, as otherwise the fish would have died before being harvested.
In 2010, BC found PRV was common in farmed Atlantic salmon, but the infection was not tied to disease. Further, wild fish are not infected with PRV, he stated.
"We tested 150 juvenile pink salmon sampled from the Broughton Archipelago in 2008. All results were negative — no virus," he said.
However, Morton said that, according to evidence presented at the Cohen Commission of Inquiry into the Decline of Fraser River sockeye, the virus was indeed found in sockeye.
