Sea lice issues cause concern

Dan Maclennan
February 12, 2010
Courier Islander

Are drug-resistant sea lice from Nootka Sound fish farms being introduced to Discovery Passage, posing an enormous threat to wild salmon and farmed fish throughout the Inside Passage?

That's a concern being raised by Alexandra Morton but rejected this week by the province and Grieg Seafoods.

Late last month Grieg announced it was making "in-season production changes to its operations in Esperanza Inlet on the West Coast of Vancouver Island, in order to implement a Harmonized Regional Management Plan for the area."

Grieg has five farm sites in Esperanza Inlet. Under-sized fish in the pens are being harvested and shipped for processing. The plan means all farms will be re-stocked in the fall with the same age class of fish.

"By doing so Grieg Seafood expects to achieve even better production, fish health, and environmental management," Grieg managing director Peter Gibson said in a Jan. 28 news release.

Just a few days before that, however, Morton says she started hearing from people that Grieg was in fact killing off all its fish in the area because they were infested with sea lice grown resistant to Slice, the chemical used throughout the coast to kill sea lice on farmed fish.

Morton says she found sea lice in very high numbers around Grieg's Esperanza farm on Jan. 31. She said there's no way the sea lice numbers should be so high in the area if the farm treated its fish with Slice in the fall, as provincial aquaculture officials tell her.

"I know they've got a lot of lice," Morton told the Courier-Islander this week. "Now the province has told me that (Grieg) treated in the fall. So in a couple of louse generations they have a serious lice problem. That is highly suggestive of drug resistance in the sea lice."

"Drug resistance is a big problem that's emerging around the world right now. It's actually in a crisis state in Norway. The lice have become resistant on the east coast (of Canada).

"I was not only concerned with the problem of the lice in Nootka Sound, but the greater concern is that they're moving those fish in trucks across Vancouver Island and processing them in a fish plant on Quadra Island. This raises the possibility that these lice eggs are going down the pipe into Discovery Passage and being distributed throughout the Discovery Islands. If they are resistant to the drug Slice that means we're going to lose the main tool to protect wild salmon from these salmon farms."

Salmon farms treat their fish with Slice in the spring in an effort to keep sea lice numbers down when out-migrating wild salmon pass through the area.

"My concern is that there is a problem in Nootka and it's being taken to the Discovery Islands and nobody is addressing this issue," Morton said. "So the only way that the people of Canada are going to find out that this is a problem is when the fish farms in the Discovery Islands go to de-louse their fish with this drug, it doesn't work, and we lose a generation of wild salmon."

But Trevor Rhodes, Aquaculture Operations Branch director for the Ministry of Agriculture and Lands, based in Courtenay, says there's no evidence of any Slice-resistant sea lice. He said Grieg treated with Slice in the fall. Rhodes said the ministry sent fisheries inspectors and their senior fish health veterinarian to the Esperanza site on Jan. 28.

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Posted February 12th, 2010