Sea lice, the scourge of salmon farmers, has cost the global aquaculture industry billions of dollars over the years. Until recently, the weapons available for farmers to defend against these natural pests of fish, consisted of various therapeutic in feed and bath treatments coupled with complicated and costly mechanical removal, which are becoming less effective over time.

Now, with support from provincial and federal governments in Atlantic Canada, Cooke Aquaculture Inc. and a team of university-based and public-sector researchers are close to fully domesticating a native “cleaner fish to more naturally reduce parasite numbers from commercial salmon farms.” According to Dr. Andrew Swanson, Vice President, Research & Development, it’s a first for North America, and could be an industry game changer.

“This innovative marine program involves raising cultured lumpfish as an effective and eco-friendly sea lice removal method,” he says. “These fish basically eat and remove lice which settle on salmon in sea cages. Lice, in large numbers, are harmful to the Atlantic salmon, the aquaculture industry, and are presently one of the most important fish health challenges that we manage.”

Cooke Vice President of Public Relations Joel Richardson added that while 98 per cent of the company’s current sea lice treatments in Atlantic Canada are mechanical and eco-friendly, the cleaner fish program provides a new, green alternative to complement the mix of existing approaches. “They could be very effective in preventing infestations from advancing, especially in the early vulnerable stages of a salmon’s life cycle,” he said. 

Although sea lice are not harmful to humans, they do harm juvenile salmon and stunt appetite and growth in adults, costing an estimated $1 billion a year to salmon farmers around the world. The total economic impacts of Atlantic Canada’s farmed salmon sector amount to just under $2 billion in output and $800 million in GDP, about $350 million in salaries for more than 8,000 workers. Says Richardson: “There is a lot at stake here.”

Swanson says Cold Ocean Salmon Inc., Cooke’s subsidiary in Newfoundland and Labrador, started working on the cleaner fish process with Memorial ten years ago, and with Dalhousie researchers for the past two years. Thanks to steady progress, he says, “We’ve invested significantly in this strategy, and begun to scale and expand the routine use of lumpfish in our salmon production farms of Newfoundland. We’ve recently started to populate our farms in New Brunswick, and eventually, we’ll move this as needed into operations in Nova Scotia and Maine. Developments here are also expected to guide best practices for cleaner fish programs at our other global farms.”

Danny Boyce, Facility and Business Manager of Memorial’s Dr. Joe Brown Aquatic Research Building, says he encountered the cleaner fish approach while investigating new ideas for the facility a number of years ago. “Aquaculture is a very pronounced industry in Atlantic Canada and Maine,” he says. “I thought cleaner fish use may be of interest if we can develop it here locally. So, I reached out to Cooke.” 

In fact, the process is proven in Norway, where salmon farmers have been using wild caught cleaner fish since the 1990s. Says Boyce: “In most salmon farming, prolonged use of therapeutants leads to resistance in lice populations and concerns over the effect on surrounding flora and fauna.”

There are still wrinkles to smooth. Dr. Javier Santander, a marine microbiologist at Memorial and one of the scientific leaders of the project, says lumpfish and cunner biology aren’t well documented, compared with other species. That makes understanding the pathogens that may affect them (and, by extension, the salmon they “clean”) and the development of vaccines challenging. “Fortunately, we’ve formed a partnership with Cooke, the Ocean Frontier Institute, Atlantic Fisheries Fund, Genome Atlantic, and the Canadian Center for Fisheries and Innovation to develop and test effective vaccines in the field, select for resistant lumpfish to infectious diseases, sequence lumpfish and cunner genomes, and profile their transcriptome in response to immunization,” he says. 

All of which, Swanson says, is “a wonderful example of a multi-level partnership harnessing nature to a commercial advantage.”

The program has received financial support from AFF, ACOA, Genome Atlantic, Canadian Centre for Fisheries Innovation, DFO ACRDP, Ocean Frontier Institute, NSERC, MITACS, as well as indirectly from Governments of NL & NS, and Canada. The specific research groups collaborating on aspects of the cleaner fish program are Memorial (NL), Dalhousie (NS), Guelph (ON), DFO’s SAB Station (NB), as well as Pronova (NS) and Belleoram Nursery (NL).