The culprit behind the rising price of salmon is about the size of an aspirin: a parasite known as the sea louse, or salmon louse. Acute outbreaks in Scotland and Norway this year have, er, eaten into the global supply of farmed Atlantic salmon. Norway, the planet’s biggest salmon producer, exported around 5% less by volume than in 2015. Globally, production fell around 9%. All that adds up to a problem that will increasingly put the squeeze on seafood lovers—and raises new questions about how to beat back the scourge of sea lice without hurting salmon, and the people who love to eat them, in the process.One technique, known as a thermolicer, plunges the salmon into a scalding-hot bath. The hot water kills off the sea lice—and also, sometimes, the fish themselves. Last year, salmon-farming giant Marine Harvest inadvertently cooked 95,000 caged salmon with a thermolicer. Though that killed 95% of the sea lice, it also left the company with 600 tonnes of dead salmon to incinerate. Along with rampant salmon deaths from pesticide treatments, the thermolicer incident caused a 16% drop in the company’s Scottish salmon output for 2016.
There are other options in the works, including lice-zapping lasers, fancy ultra-large-scale pens, and delousing vessels called hydrolicers. But even with the preponderance of government funding from leading salmon-farming countries, new technology is expensive to develop. And for the salmon-farming giants like Marine Harvest, Nova Sea, and others, scale remains a challenge. Meanwhile, a promising sea lice vaccine hasn’t yet borne fruit.
Worse, the conditions that invite sea lice seem to be on the rise. The sea lice life cycle accelerates in warmer temperatures. So it’s hardly surprising that a recent study found that unusually balmy seas helped encourage the 2015 sea lice epidemic that swept British Columbia, Canada.
This all adds up to a pricey problem. And given that the sea lice spread shows few signs of abating—nor does the outbreak of another salmon blight, amebic gill disease—consumers are likely to face steeper salmon prices in 2017. Analysts at the Norwegian bank Nordea expect global supply of farmed Atlantic salmon to stay below 2015 levels for the next three years.
The sea lice epidemic isn’t just hurting fish, farmers and consumers—it also takes a toll on other sea life. Slice is poisonous to crustaceans, though its long-term effects have not been researched. In 2013, a subsidiary of Cooke Aquaculture, one of North America’s biggest salmon producers, pleaded guilty to killing hundreds of lobsters with its use of cypermethrin, a delousing chemical used in Europe but banned in Canada.
The most egregious ecological problem, however, is the fact that the teeming sea lice reservoirs created by farming are devastating wild salmon populations. In that sense, sea lice and humans have something in common: an appetite for Atlantic salmon that nature simply can’t sustain.
