Cold water kills 10,000 salmon at Cooke fish farm near Liverpool

Kelly Cove Salmon has scooped 10,000 dead Atlantic salmon from its fish farm near Liverpool on Nova Scotia's South Shore.

The fish died last week due to cold temperatures in their ocean pens at the company's Coffin Island site in Liverpool Bay.

Joel Richardson, spokesperson for Kelly Cove's parent company, Cooke Aquaculture, said technically the die-off isn't classified as a "superchill" event because the water temperature didn't fall to the required threshold of –0.7 C. Superchill occurs when the water temperature drops to the level that fish blood freezes.

The ocean temperature at the site did, however, fall to –0.6 C last week.

Richardson said the die-off is a concern to the company, but losses due to cold water happen every five years or so. 

"We obviously take a lot of care and pride in farming fish and the sea farming environment," he said. "But working with livestock and agricultural production, when you're growing fish and any other type of animals, there are occurrences that … do cause problems."

The last time a Cooke Aquaculture site in Nova Scotia had a case of superchill was in 2015.

The Coffin Island site consists of 14 cages that usually contain a total of about 400,000 fish, so the die-off last week represents about 2.5 per cent of the stock. The fish were removed and taken to a rendering plant in the province to be composted.

Richardson said a die-off of 10,000 fish due to cold weather is considered relatively small.

Cooke reported the incident to the municipality, the provincial Fisheries and Aquaculture Department and the federal Department of Fisheries and Oceans.

A spokesperson for the province said samples of the fish were analyzed by the department's veterinarians and early results indicate the deaths were due to "cumulative weather events."

Brian Muldoon is with the group Protect Liverpool Bay, which is opposed to the farm.

He can see the operation from his property and has watched over the past week as the dead fish are removed from the pens.

"It's not acceptable," he said. "In any other industry if a farmer did not have a barn to protect his cattle in the winter, there would be an outcry and he'd be shut down and sued.

"If our water is too cold in the winter, they should not be allowed to be here."

Expansion plans

Cooke is hoping to expand the site in Liverpool Bay to a total of 60 cages with 1.8 million Atlantic salmon.

Richardson said it could take a year or so to get all the required approvals.

Muldoon said the die-off last week raises concerns about whether the company can manage a larger operation.

"This is just one with one small farm," he said. "How are they going to handle two new farms bigger than this one?"

David Dagley, the mayor of the Region of Queens Municipality, said council has not taken a position on the expansion proposal, but it did submit a list of 24 questions to Cooke last month about the potential economic and environmental impacts of an expansion. The company provided responses to those questions last week.

Dagley said residents have spoken out both in support of the project and against it.

"Trying to balance out the majority who are silent and the minority who are vocal, council decided that the best thing to do is let the science inform the process," he said.