Sea lice from fish farms threaten Fraser River sockeye: biologist

Pieta Woolley
Georgia Strait
March 23, 2009

Sea lice from fish farms may be a greater threat to Fraser River sockeye salmon stocks that conservationists previously thought.

That’s according to research conducted by the Coastal Alliance for Aquaculture Reform and the Raincoast Conservation Foundation.

Raincoast biologist Michael Price said that sockeye salmon from as far up the river as Prince George are catching sea lice from fish farms in the Pacific Ocean, Strait of Georgia, and Broughton Archipelago.

Price told the Straight in a phone interview from Clayoquot Sound today that the recent decline in sockeye stocks may be attributable to the sea lice.

Those fish are small juveniles when they migrate to the coast.

In Scotland, Ireland, and elsewhere in Europe, he said, scientists have found that sea lice can kill juvenile salmon and trout, which are 14 to 20 centimetres long.

In B.C., these juvenile salmon are about 10 centimetres. So in theory, he said, they’re even more vulnerable.

“We’re not sure whether juveniles are being lethally effected,” Price said. “We need to do the science.”

Price was careful to state that the research has not been peer reviewed or published yet, and the results of the study are preliminary.

But the scientist said the province should be alarmed.

In 2007, about 60 percent of the sockeye sampled east of Vancouver Island-in the heaviest salmon farming region in the province-were from the Fraser River. In 2008, 90 percent were from the Fraser, according to Price.

“Salmon is the thread that holds this coast together,” he said.

Until four years ago, Price studied B.C. bears and wolves, but he shifted his focus to salmon because they’re key to conserving terrestrial carnivores.

“They are connected to almost all other life that appears on this coast….Sockeye are of high economic, social, cultural, and spiritual significance to not only First Nations but people throughout this province. It’s a food source for many, many people. It’s a food source that could be eliminated.”

According to the B.C. Ministry of the Environment, aquaculture’s contribution to the provincial GDP is $71.4 million; capture fisheries contribute $135.4 million. B.C. is the world’s fourth largest producer of farmed salmon.

Price said that needs to change.

“We know what to do. We can close farms,” he said, noting that Fisheries and Oceans Canada has received several applications to expand fish farms. “Or, we can reduce the number of fish they produce. Or, we can find the technology to move them onto land.”

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Chelsea Greer hanging a wildlife camera.