Are BC salmon riddled with sea lice?
The price of salmon has shot up more than 15 per cent over the last three months, thanks to fish stocks being hit worldwide by an outbreak of sea lice.
In Norway and Scotland, two of the world’s largest suppliers of salmon, sea lice outbreaks have made prices rise by a full 50 per cent, coupled with a huge algae bloom in Chile, the world’s second biggest producer of farmed salmon, and global production is down by nine per cent.
But the market for Pacific salmon is not likely to see the same price spikes, according to Glen Spain of the Pacific Coast Federation of Fishermen’s Associations, who says that sea lice has so far been less of a scourge for Pacific Coast salmon.
“As long as we don’t see the kind of outbreaks we’ve had in the past, (and) we don’t find a spread from the Atlantic to the Pacific, we will be in reasonably good shape,” said Spain to the Seattle PI.
The tiny, naturally occurring parasite, found in both wild and farmed salmon, last proved to be a menace on the West Coast in 2015, when infestations were at their highest in five years.
But the role played by aquaculture practices in the proliferation of see lice, both in wild and farmed fish, is a topic for debate. It’s known that the high concentrations of salmon stocks in aquaculture pens make for ideal breeding grounds for sea lice, which can then drift out into the wider ocean. Farmed salmon start out their lives within aquaculture pens on land and are then brought to ocean net pens, still lice-free, as juveniles. Once in the ocean, however, the fish are exposed to sea lice through wild salmon stocks.
But a report last year from the BC Salmon Farmers Association maintained that the 2015 outbreak should not be pinned on salmon farms, stating that sampling showed that most of the infestations of the sea lice were occurring in areas where there was no active salmon farming. The outbreak was instead blamed on warmer water temperatures, higher salinity and larger returning infested salmon.
“[In 2015] there were some specific circumstances that lead to increases in sea lice abundance across the board, including areas where there are no fish farms,” said Crawford Revie, a Canada Research Chair and professor at the Atlantic Veterinary College at the University of Prince Edward Island, to the Vancouver Sun.
Indeed, climate change and warming ocean waters are expected to increase sea lice outbreaks worldwide going into the future, yet fish farming practices are not helping matters in the meantime, says Spain.
“The real problem is that the net-pen operations are simply asking for that kind of outbreak, with all those fish confined in a very small area. Their natural state is to be distributed over the whole ocean,” says Spain. “If you have a lot of fish confined to a small area, the sea lice are endemic. … They build up a large population of sea lice, which then drift out of the sea pen and into local, migrating fish.”
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I’m not sure you are doing any favors to the existing body of science with the above article. Is the title solely to draw in the reader? or do you honestly feel you have portrayed the views of experts on the extremely complex ( and for the most part unknown) host/parasite relationship among sea lice, wild salmon, and farmed salmon in BC.? Is there a reason why you quote Spain 4 times despite having no expertise on salmon or sea lice ( No published papers) ? Crawford Revie is indeed an expert in his field of epi-informatics with hundreds of papers published ; many on sea lice and salmon. If you asked him if ” BC salmon stocks were or have ever been diminished by sea lice?. He would likely say ” Based on the current evidence…. we have absolutely no idea if there is affect at a population level nor how to measure it.