Humans and bears aren’t the only animals that find salmon delicious. Salmon lice, small marine crustaceans, attach themselves to the fish and make a meal of their blood, mucus, and skin cells (not my favorite part of the salmon, but it takes all types). These parasites are also the scourge of Norwegian salmon farmers, who keep their shoals in net pens in the Atlantic Ocean.
Removing them is required by law, but it’s a real pain. They’ve become resistant to pharmaceutical deterrents and traditional delousing methods involve hot water baths, scrubbing, and general rough handling, which can damage or kill the fish. While some farms have employed cleaner wrasses to feed on the bloodsuckers, they’ve proved difficult to keep alive.
Read more: “Cocaine Fish: How Salmon Behave When Amped Up on Coke”
So what can be done?
Obviously the only solution is zapping the parasites with a high-powered laser guided by artificial intelligence. At least that’s what the company Stingray Marine Solutions AS came up with. According to the company, their optical delousing system is already watching over 20 to 25 percent of farmed Norwegian salmon.
The system consists of robotic “submarines” that float in the net pens. The robots bathe the salmon in blue light to enhance the contrast of the lice against the salmon skin which allows the artificial intelligence to detect the parasites. Once the target is acquired, a high-powered laser capable of firing five pulses per second superheats the louse, killing it.
It looks incredibly cool in action:
But does it work?
Per a study the company paid for, it does. A team of their own researchers combined public data on weekly lice counts and treatments from 845 Norwegian sites with the manufacturer’s records of which sites and weeks used optical delousing. They found sites with the laser system in place required fewer additional delousing treatments compared to sites without them. “Our results show that sites relying on optical delousing exhibit a 50 percent lower weekly treatment probability,” the researchers wrote.
However, a survey of salmon farmers conducted by the Norwegian Veterinary Institute found mixed results. According to their results, 75 percent of salmon farmers had experience with lasers, and 17 percent of those said they helped them avoid at least one or two delousing treatments. But 56 percent of laser-using farmers said they weren’t sure if they were having any effect. In open-ended questions, the farmers reported the systems were better at delousing when lice populations were low. Additionally, some said the software may be undercounting the parasites (compared to manual counting), which makes their effectiveness difficult to determine.
So lasers may not be the ultimate solution to Norway’s salmon lice problem (yet). But they do look cool doing their jobs.
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Lead Image: Stingray Marine Solutions AS
