More than 90,000 salmon being farmed in an open-net aquaculture pen on Newfoundland's south coast died over the weekend, the Department of Fisheries, Forestry and Agriculture announced in a media release Saturday.
The event occurred at a site known as "the gorge," which is operated by Mowi's Marine Harvest Atlantic Canada, and was caused by "sudden low dissolved oxygen levels."
The dead fish have been removed from the site. The release said mitigation measures, including deeper nets and aeration equipment, "improved survivability" during the die-off.
'A reckless approach to regulation'
Mark Lane, executive director of the Newfoundland and Labrador Aquaculture Industry Association, called the event "very unfortunate," but said die-offs are unavoidable in any kind of farming, whether marine or terrestrial.
"We have to remember that Newfoundland and Labrador has one of the most challenging environments for farming, whether that's farming fish or farming vegetables," he said.
But one critic says the high number of mortality events in the province's aquaculture industry has less to do with weather, and more to do with what he calls "a reckless approach to regulation."
"The province should be a regulator," said Leo White, spokesperson for the Newfoundland and Labrador Coalition for Aquaculture Reform. "They're not really acting as a regulator in the true sense of the word."
Friday's die-off was only the latest in a series of mortality events on Mowi-owned aquaculture farms, White noted.
Many questions, few answers
In August 2019, 2.6 million salmon died in pens operated by Northern Harvest Sea Farms, a subsidiary of Mowi.
Those events led to the company having its 10 farming licences suspended and later reinstated. It also resulted in policy changes, including a requirement that aquaculture companies report die-offs affecting more than 10 per cent of fish populations.
But White questions the efficacy of those measures.
"There was all kinds of talk afterwards by the company about how they were going to make the nets deeper — there was going to be irrigation equipment and this would not be happening in the future," he said. "But here we are. Another mass die-off."
White also questions the death toll reported by the company: 92,700 out of 900,000 is just about 10 per cent, he noted.
"It would be interesting to know just how the number of dead salmon was determined," White said in a media release issued by the N.L. Coalition for Aquaculture Reform. "[It's] also interesting that the number is 10 per cent of the total stock, just above the threshold for mandatory reporting."
White also doesn't buy the company's claim that a "precipitous" drop in oxygen caused the die-off.
"This sounds like they were caught unaware that salmon packed tightly into a fixed net pen need a dependable supply of oxygen," he said. "They're the biggest aquaculture company in the world. You would think that they'd have this resolved."