The study was conducted to address concerns about ISA possibly appearing in Washington State’s water bodies and potentially harming the state’s salmon stocks. The testing is part of a two-year monitoring programme specifically designed to detect ISA and will last for another year.
To arrive at its conclusion, the study improved testing protocols for the ISA virus to better detect it in a host of fish species. It used samples from wild and hatchery-produced Pacific chinook, coho, sockeye, chum and steelhead as well as farm-raised Atlantic salmon.
ISA was not identified in any of the more than 900 wild and farmed fish tissue samples that were analysed as part of the study.
“Our traditional testing protocols would have detected most – but not all – of the disease-causing strains of ISA virus,” said John Kerwin, Fish Health Programme manager for the WDFW. “So we expanded our programme to better detect whether any strain is present in a variety of fish species in Washington. The good news is all the samples came back negative for the virus.”
Mary Ellen Walling, executive director with the BCSFA, was not surprised.
“This study reinforces the findings of the Canadian Food Inspection Agency (CFIA) and the results of the Provincial Government’s labs that ISA has not been found in the waters of the Pacific Northwest or in BC,” she said.
The BCSFA’s members say they participate in regular testing of their farm-raised fish for ISA. Of some 1,000 fish tested in 2012, all returned negative results, they said.
“We know all the world’s oceans are connected, so a virus from another part of the world may eventually make its way to BC,” said Walling. “That’s why rigorous screening and this kind of on-going testing is important. It means that if a virus is detected it can be found early and properly dealt with.”