Reference photo of salmon in a net pen. More than 1 million fish at two Mowi sites in Atlantic Canada may have to be removed from cages if suspected ISAv is confirmed. Photo: Mowi.

ISAv suspected at Mowi farms with more than 1m fish

Mowi is facing the prospect of prematurely slaughtering more than 1 million salmon after the suspect detection of infectious salmon anaemia virus (ISAv) at two sites off the south coast of Newfoundland.

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ISAv is suspected at the McGrath Cove North and Ironskull Point sites.

In each case, the detections of suspected ISAv occurred in one Atlantic salmon from one cage at each site that was sampled through the Provincial Government Department of Fisheries, Forestry, and Agriculture’s species-specific aquatic animal health surveillance programme, said Mowi.

‘Following best practices’

The cage at the McGrath Cove North site from which the suspect detection occurred contains approximately 185,000 fish, and the marine site is comprised of three cages containing a total population of approximately 560,000 fish.

The cage at the Ironskull Point site from which the suspect detection occurred contains approximately 225,000 fish, and the marine site is comprised of three cages containing a total population of approximately 500,000 fish.

“Northern Harvest Sea Farms (Mowi’s subsidiary in Atlantic Canada) is working with federal and provincial authorities and following best practices in the handling of these farms,” said a Mowi statement on the Newfoundland Aquaculture Industry Alliance website.

Sites quarantined

“These marine sites have been quarantined, and the company is following all regulatory requirements.

“ISAv is a naturally occurring virus and is not a human health issue or a food safety issue.”

In August, Mowi slaughtered approximately 200,000 salmon in one of three cages at its Cinq Cove site, also located of the south coast of Newfoundland, after ISAv was confirmed in two fish from the pen.

Fish from the two other cages on the site, containing a total of 400,000 salmon, tested negative.

Hatchery cull

In April, Mowi quarantined its hatchery at Stephenville, NL and culled 450,000 juvenile salmon after sampling identified eight fish as positive for pathogenic ISA, and six fish as positive for non-pathogenic ISA.

Cooke Aquaculture, which farms salmon off the south coast of Newfoundland under its Cold Ocean Salmon Inc. subsidiary, has also had problems with ISAv this year, and has removed fish from farms at North of Killbuck Cove (340,000 salmon), Seal Cove (234,000), Robin Hood Cove (611,000) and Grip Cove (485,000).