2 more mass salmon die-offs reported off south coast of Newfoundland

Two more mass mortality events have been reported at Newfoundland fish farming sites, both at sites on the island's south coast.

Cooke Aquaculture, who operates Cold Ocean Salmon at the Olive Cove site in Hermitage Bay, reported that around 47,000 fish died over a multi-day period beginning on July 19.

Joel Richardson, vice president of public relations, said both warm water and sea lice played a factor in the event.

"A few key areas around Newfoundland, not unlike other areas in Atlantic Canada, can get warm. And the water affected one of the crops of our fish at one of our sites in a few specific cages. And unfortunately those fish perished," Richardson told CBC Radio Thursday.

"When you kind of combine the high temperatures with this localized sea lice in the area that's there on an ongoing basis, it certainly can be problematic. And it was problematic in this case."

Days earlier, Richardson said another mortality event happened during a smolt transfer at its Grip Cove site, near Hermitage, on July 16.

He said a mechanical issue during the transfer resulted in between 17,000 and 18,000 juvenile fish dying. Losing fish during smolt transfers isn't uncommon, he added, but the amount of fish lost was abnormal in this case.

"It's unfortunate that you have crop loss and you lose fish. But, you know, that is the nature of farming and growing food," Richardson said.

Another player in Newfoundland salmon farming, Mowi Canada East, reported a mortality event caused by a period of increased water temperatures on Monday. At least 17,600 fish died in that event.

Gideon Pringle, Mowi Canada East's managing director, told CBC News in an email on Thursday that the event was isolated to a single farm and quickly resolved during the farm's final days of harvesting.

When asked what farming sites are doing to combat rising water temperatures, Richardson said temperatures are monitored on a daily basis.

Richardson added that while he said he hasn't seen a dramatic increase in water temperatures during Cooke's time in Newfoundland, mortality events will continue to happen as farming continues.

"It's not cause for great environmental concern. We go through the process, we remediate the site, and the site is cleaned and ready to be farmed and fished again," he said.

"We also have a lot of technology in the sea cages. Underwater cameras, temperature sensors in real time that provide data back to the fish health team and the technicians. So they're monitoring that on an ongoing basis.... It's just something that we have to be mindful of."

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