Cyr Coutourier says there are many possible reasons why the Cooke Aquaculture held back on expansion plans.

Cooke Aquaculture is putting the brakes on a salmon farm expansion in Nova Scotia, though the company says it has nothing to do with a suspected outbreak.

Last week, a salmon farm owned by the company was quarantined after the discovery of a suspected case of a destructive virus called infectious salmon anemia (ISA).

Cooke Aquaculture had big plans for fish farming Shelburne County, but an expansion there for 700,000 fish has been withdrawn.

Local opponent Sindy Horncastle said the timing was suspicious.

"We thought it was a very large coincidence that they were withdrawing that lease application at the same time there is a suspected ISA outbreak at the mouth of Shelburne Harbour," she told CBC News.

The company  — which operates in Shelburne as Kelly Cove Salmon —wouldn't say which of its Nova Scotian fish farms was the source of the suspected virus.

The company has destroyed two cages of salmon as a precaution while authorities investigate. ISA has not yet been confirmed by the Canadian Food Inspection Agency.

No explanation

The company's letter withdrawing its expansion offers no explanation.

Cooke Aquaculture say there is no connection between the decision to delay expansion here in Shelburne harbour and ISA. It says it is "phasing in" its application and its plans remain unchanged.

"The decision to delay the application process for the site near Shelburne was made more than 30 days ago and that information was communicated to the appropriate regulators at that time," Chuck Brown, spokesman for Cooke Aquaculture, said in an email to CBC News.

The Department of Fisheries and Aquaculture confirmed the application delay Monday.

"We were informed of the company's intention to delay the application process for Middle Head on Dec. 22, 2011," said Brett Loney, spokesman for the department.

The former president of the Canadian Aquaculture Association said there are many reasons why Cooke Aquaculture would withdraw, including a saturated market and lower prices.

"A company like Cooke has production actually in Maine, New Brunswick, Nova Scotia and Newfoundland and Labrador, so maybe it has sufficient sites, and maybe it doesn't need this additional site," said Cyr Coutourier.

Coutourier said the destruction of the salmon was just a precaution, though it was an expensive one.

"It represents several million dollars loss to the company for sure," he said.

Tests to confirm ISA are expected to take several weeks.