Grieg Seafood Newfoundland on Tuesday said it will cull one million fish and postpone the first transfer of fish to sea until Spring 2022 after finding a positive sample of infectious salmon anemia (ISA) at its smolt site.

The decision is taken based on a precautionary approach and to reduce risk, the company said, noting that it plans to develop salmon farming operations in Placentia Bay "gradually and responsibly."

During a routine sampling of the fish scheduled to transfer to sea from the Marystown facility this summer, one fish provided a suspect detection of ISA.

Over the last few weeks, 295 additional samples have been collected and analyzed by Provincial Veterinary Authorities, said Grieg, and all samples have provided negative results and no ISA was detected.

However, Placentia Bay is a promising area for salmon farming with no known history of ISA so Grieg Seafood Newfoundland will not risk introducing the virus into the environment, it said.

As a result, almost one million fish that was scheduled for sea transfer this summer, will be culled, the company announced.

All of these fish are in the same recirculating aquaculture system (RAS) as the one fish with the detection, and the company "would not have been able to maintain its fish health and welfare standard in sea should the virus exist in this fish group," it said.

A thorough review has been initiated to find out why an ISA detection occurred, and measures will subsequently be put in place to avoid similar occurrences in the future, said Grieg.

The financial impact of the postponement is minor, the company said, as the first group of fish had few individuals compared to regular operations.

During the spring and summer of 2022, around 3 million fish are due to be transferred to sea, in accordance with the original schedule.

These eggs and fish are currently growing well in a separate building in the Marystown facility. The fish will be harvested in 2023 and 2024.

Grieg Seafood Newfoundland’s 2025 harvesting target of 15,000 metric tons remains unchanged.

"We have said from the beginning that we will develop our farming operations in Placentia Bay gradually, responsibly and sustainably," said Knut Skeidsvoll, managing director of Grieg Seafood Newfoundland.

"As such, we believe it is right to apply the precautionary approach in this situation and postpone the transfer to sea to the spring of 2022."

Even though none of the additional 295 samples detected any virus, Grieg does not want to risk introducing ISA into the environment.

"Our plans and vision beyond this first group of fish have not changed, and we are using the experience gained to improve for the next generation," added Skeidsvoll.