A fish farming group says open-ocean aquaculture poses little threat to wild populations and they are 150 times cheaper to operate, disputing a call from some wildlife groups to move to land-based operations.
Pamela Parker, the executive director of the Atlantic Canada Fish Farmers Association, said it only takes a few fish to shut down an entire operation.
"Well, as experts will tell you, there's not necessarily any evidence that these fish that have been harvested actually have the ISA virus. What happens is the fish were in a farm that — all you need is very few fish, two or three fish to be diagnosed with this virus — means that the whole facility to be quarantined," she said.
"So these fish ... even though they may have been around the virus, were not diseased and were perfectly safe for human consumption."
Wildlife groups like the Atlantic Salmon Federation are pushing for changes to the industry following a controversial decision by the Canadian Food Inspection Agency.
The CFIA recently allowed Cooke Aquaculture to continue to raise open-pen salmon after they contracted infectious salmon anemia (ISA).
The disease kills up to 90 per cent of infected fish but poses no risk to human health, according to the CFIA.
The ASF said moving to land-based tanks would eliminate environmental threats and the spread of disease into wild populations.
But Parker argues open water aquaculture farms are monitored very closely and that's how the ISA outbreak at the Shelburne, N.S. facility was caught so quickly.
"CFIA works very, very closely with the provincial vets and the salmon farming companies to determine the best management option and it's generally done on a case-by-case basis as we learn more and more about this virus," Parker said.
She said there are many factors considered before the decision is made to either cull or allow an infected fish to grow to market size to be sold.
"There's the size of the fish on the farm, the risk that the fish on that farm would have to other fish on that farm and/or other farms and to wild species that are also in the environment . . . all of which is available publicly," said Parker.
"What we're concerned about is their opposition. We're concerned that perhaps this is just another move to see salmon farms moved out of the ocean — which we do not believe is either a good idea from an environmental stand point or a fish health stand point," she said.
The cost of running a fish farming operation on land compared to open-ocean cages is not comparable, Parker said.
She estimates raising fish on land would cost 150 times more than the market price.
"It's one of those most heart-healthy foods a person can eat and people simply cannot afford a salmon that costs 150 times more than the current market price," she said.
She said she recognizes that as technology develops within the industry, it may become most cost-effective to raise salmon on land.
"We also want to remember we have a very strong and sustainable industry in Atlantic Canada. It supports the economic diversity for multiple coastal communities and if we go to closed containment there is neither the land base, nor the fresh water base that's required to support these farms," she said.
Critics note ISA only becomes a real problem when it reaches the farmed fish environment because it spreads so quickly.