Fish Farm Induced Sea Lice Could Kill Millions Of Salmon

Fish Farm Induced Sea Lice Could Kill Millions Of Salmon

Independent researcher Alexandra Morton claims a sea-lice infestation off the coast of British Columbia, Canada, will kill “hundreds of thousands if not millions” of wild salmon this spring.

The controversial biologist, who in 2001 sounded the alarm about sea-lice infestations on the B.C. coast, is once again blaming fish farms for the outbreak.

She says densely packed farm pens serve as reservoirs for the lice, which drift with the tide, infecting passing wild salmon. Her claims highlight that farmed fish may not be the solution it claims to be, especially when it follows the same risky habits of large scale commercial farms on dry land.

Industry lobbyists for the farms say that when lice are detected, fish are promptly treated with SLICE, a pesticide that is 95 per cent effective. The practice raises further questions about the sustainability of the practice, given it means dumping chemicals into the open ocean.

But Ms. Morton counters that she has been collecting samples of young pink and chum salmon at the same three sites near salmon farms since 2001, and is now seeing some of the highest numbers of sea lice.

“I’ve had a crew out there since April 4 and we were very surprised to see heavy concentrations of sea lice,” she said Wednesday. “We look at 100 fish at each site, so 50 pink and 50 chum and … 94 per cent are infected.”

Ms. Morton said the sample sites are all located near fish farms and the tiny, juvenile wild salmon, which recently hatched from eggs in nearby rivers, average two lice a fish, which is enough to kill them at this early stage of life.

“For the past seven years we saw excellent low levels of lice. Suddenly, this year, we are back up,” she said. “Now, we don’t know whether the salmon farms failed to treat, or if their treatment failed.”

Sean Godwin, a Simon Fraser University doctoral biology student, published a paper last week that showed wild juvenile sockeye salmon infected with sea lice have a tougher time surviving.

“We found sockeye salmon highly infected with sea lice are less able to compete for food than lightly infected or uninfected fish,” said Mr. Godwin, whose study showed infected fish were able to consume about 20 per cent less food on average.

Mr. Godwin said his research did not try to determine the source of the lice he found on wild sockeye.

In a statement, Chief Bob Chamberlin, chair of the First Nations Wild Salmon Alliance, said he was “deeply concerned” by reports of sea-lice infestations. He called for an end to the expansion of fish farms on the B.C. coast.