Blood-suckers: these tiny parasitic sea monsters are plaguing the global salmon industry

Salmon farmers are in a high-tech war against sea lice, with new weapons including underwater drones armed with lasers

PUBLISHED : Monday, 18 September, 2017, 2:52pm
UPDATED : Monday, 18 September, 2017, 11:12pm

Salmon have a lousy problem, and the race to solve it is spanning the globe.

A surge of parasitic sea lice is disrupting salmon farms around the world. The tiny lice attach themselves to salmon and feed on them, killing or rendering them unsuitable for dinner tables.

Meanwhile, wholesale prices of salmon are way up, as high as 50 per cent last year. That means higher consumer prices for everything from salmon fillets and steaks to more expensive lox on bagels.

The blood-sucking lice are actually tiny crustaceans that have infested salmon farms in the US, Canada, Scotland, Norway and Chile, major suppliers of the high-protein, heart-healthy fish. Scientists and fish farmers are working on new ways to control the pests, which Fish Farmer Magazine stated last year costs the global aquaculture industry about US$1 billion annually.

So far it has been an uphill struggle that is a threat to a way of life in countries where salmon farming is a part of the culture.

“Our work has to be quicker than the evolution of the lice,” said Jake Elliott, vice president of Cooke Aquaculture in Blacks Harbour, New Brunswick.

Farmers worldwide consider sea lice the biggest threat to their industry and say the persistent problem is making the fish more expensive to consumers. Farmed salmon was worth nearly US$12 billion in 2015, according to the Food and Agriculture Organisation of the United Nations.

The only hope is to develop new methods to control the spread of lice, which are present in the wild, but thrive in the tightly packed ocean pens for fish farming, said Shawn Robinson, a scientist with the Canadian Department of Fisheries and Oceans.

“There are not enough tools right now to allow the farmer to really effectively deal with it,” Robinson said.

The worldwide supply of salmon fell almost 10 per cent last year, with Norway, the largest producer in the world, especially hard hit.

Norwegian farmers are looking to use new closed-in pens that resemble giant eggs instead of typical mesh pens. Scottish farmers have deployed a device known as a Thermolicer to warm the water and detach the lice from fish. And farmers in North America and Europe are experimenting with using species of “cleaner fish” to coexist with the salmon and eat the lice.

Research about farming salmon along with mussels, which researchers have found will eat larval sea lice, is underway. Underwater drones inhabit the other end of the technological spectrum, zapping lice with lasers to kill them. That technology was developed in Norway and has been used there and in Scotland.

On the shores of Beaver Harbour, New Brunswick, Cooke engineer Joel Halse stood recently aboard a US$4 million vessel containing a series of tubes that send 300 salmon a minute on a winding journey while dousing them with warm water to remove lice.

Halse, who likened it to a “waterslide park” for fish, said the fish farming industry has no choice but to try such innovations.

“The cost to the salmon farming industry from sea lice is huge,” he said.