[HALIFAX, NS] — A suspected outbreak of a virus at a Nova Scotia fish farm highlights the risks involved in allowing wide-scale expansion of the aquaculture industry, a conservation group said Monday.
Susanna Fuller of the Halifax-based Ecology Action Centre said the provincial government should reconsider the industry's use of open-net pens after a seafood company reported a suspected case of infectious salmon anemia.
Cooke Aquaculture, based in New Brunswick, said it killed salmon in two cages after it detected the suspected outbreak on Feb. 10 at one of its nine fish farms in the province. Tests are being conducted to confirm whether the virus is present.
"This particular issue shows this industry is vulnerable," Fuller said in an interview.
Fuller said the government should consider increasing the use of closed containment tanks as a more ecologically sensitive option. She said there are three land-based tanks in the province and expanding their use would mean the end of using the marine environment as a "toilet" for salmon farms.
"Closed containment basically means the companies have to pay for their environmental impacts," she said. "They have to look at sewage treatment ... and all of the things they would be getting for free from the ocean."
But Brett Loney, a spokesman for the province's Department of Fisheries and Aquaculture, said it was too early to say whether the department would change its policies.
"It's really too early to speculate on any larger implications for the department or for the Nova Scotia aquaculture industry," said Loney. "These are suspect cases at one facility."
Loney said the department was working with the Canadian Food Inspection Agency to "heighten" surveillance and testing at fish farms across the province since the suspected case of infectious salmon anemia. However, he said officials didn't know how long the suspected virus may have been present before it was reported.
Jonathan Carr, a biologist with the Atlantic Salmon Federation, said early detection would be key to containing any potential outbreak of the virus.
"The longer you wait and if the infection does prove positive, then there's the possibility that it could have spread through the water column several kilometres to another cage site," said Carr.
He said generally, divers check farm sites on a regular basis to look for dead or sick fish. He said those found are removed immediately for testing.
Cooke Aquaculture has said it reported the suspected outbreak following routine tests of its stocks.
The company did not return a call Monday to comment.
But the company sent an email saying it delayed an application to expand a fish farm in Shelburne Harbour on the province's southwest shore before the suspected outbreak was detected. No reason was given.
Loney said the department was informed of the company's intention to delay its application at the Middle Head site on Dec. 22.
The Canadian Food Inspection Agency says infectious salmon anemia is not a human health or food risk, but it can kill up to 90 per cent of infected fish, depending on its strain.
Opponents of the aquaculture industry have expressed concerns that the presence of salmon anemia could link wild salmon decline with fish farms. A European strain of the virus devastated fish farms in Chile, but it's not clear whether the virus affects wild salmon.
The source of the disease remains unknown. Critics of salmon farms blame the industry, but the industry vigorously contests the allegations.