Cleaner fish R&D at Memorial University of Newfoundland helps spawn new industry

Published: December 14th 2021

Newfoundland’s emerging cleaner fish industry to control sea lice infestations in Atlantic Canada’s farmed salmon has direct links with ongoing genomic research on lumpfish and cunner at Memorial University of Newfoundland’s Department of Ocean Sciences.

Marbase Marystown Inc., also known as Marbase, the company building North America’s first lumpfish hatchery to anchor its aquaculture services hub at Marystown, N.L., acknowledges on its website the reason it settled on lumpfish, as its cleaner fish of choice. It was due in part, to “development work on lumpfish that has taken place at Memorial University’s Ocean Science Centre.” The OSC is home to North America’s leading cleaner fish R&D facility.

Paul Antle, Chairman and CEO of Marbase explained it this way: “Memorial University’s Ocean Science Centre has developed decades of data around lumpfish husbandry and is considered a critical library of research as we establish Canada’s first commercial lumpfish hatchery. The partnership between the OSC and Marbase is a key element of that commercialization program. Not only do we value the historical research, but the potential opportunities in further genomic research, as we grow out our facility and refine the genetic characteristics of the ideal lice-eating lumpfish.”

“Basically, cleaner fish are another tool in the tool box for the industry,” explains Danny Boyce, Facility and Business Manager of Memorial University’s Dr. Joe Brown Aquatic Research Building. He points out chemical therapeutants, mechanical delousing and sea lice skirts are also available options, for use alone or in some combination, to deal with sea lice, the widespread marine parasite now costing salmon producers up to $150 per tonne in estimated annual losses and treatments. In Canada last year that figure translated into an $18 million cost to producers. The parasite feeds on the mucus, blood and skin of salmon, with harmful or fatal results for the infected fish.

Industry interest and demand for cleaner fish – species like cunner and lumpfish that thrive on sea lice – is on the rise, as a biological and environmentally friendly component in the arsenal against the pest. The Marbase lumpfish hatchery expects to start with initial annual production of three million individuals and the potential to expand to five million.
Cleaner fish have already made their mark in farmed salmon operations in Norway, the United Kingdom, Ireland and the Faroe Islands.

In the absence of a North American commercial lumpfish hatchery, Mr. Boyce’s facility has basically market tested the fish in Atlantic Canada by supplying relatively small-sized lumpfish on a limited basis to Cooke Aquaculture in Nova Scotia, Mowi Canada East in New Brunswick and Grieg Seafood in Newfoundland and Labrador. Demand has now outstripped the facility’s capacity for supply. Commercial sales were a sideline to its main focus of cleaner fish R&D purposes, under Memorial’s Department of Ocean Sciences Research Production Program.
Here is where the research team headed by Dr. Javier Santander, a marine microbiologist and Associate Professor in the Department of Ocean Sciences at Memorial University has made its mark.

Working in partnership with Cold Ocean Salmon, a subsidiary of Cooke Aquaculture Inc., and with funding from Genome Canada, the Atlantic Canada Opportunities Agency and Newfoundland and Labrador’s Department of Industry, Energy and Technology, the team has used lumpfish and cunner from the facility to sequence their genomes. It was an achievement made possible by Genome Atlantic’s participation in Genome Canada’s Regional Priorities Partnership Program.

Now sequencing data are available to evaluate the species’ characteristics for commercial cleaner fish deployment. “We already have the information for the development of several biomarkers that will impact broodstock selection, diet formulation, and fish health,” said Dr. Santander. “This will not only impact Marbase, but the entire cleaner fish industry,” he added.

Essentially the team’s research efforts are now directed at removing obstacles that have precluded wider use of cleaner fish in farmed salmon operations. One of the biggest challenges has been bacterial infection, but Dr. Santander said “we are very near,” to solving the lumpfish’s high susceptibility to Vibrio anguillarum, the bacterial pathogen most often found in lumpfish and the cause of vibrosis, a deadly haemorrhagic septicaemic disease.

“We have an effective vaccine that has been tested several times and soon will be evaluated in the field,” he said. Furthermore, he said, plans are afoot to develop a certified vaccine unit at Memorial University of Newfoundland to complete certification requirements for the formulation.

After evaluating commercial and experimental “in house” vaccines (designed in previous research) against Vibrio anguillarum, Dr. Santander said, “we determined that one of our preparations conferred superior protection.” His research group is now processing the data for transcriptomic profiling of the lumpfish response to the effective immunization.

The team is also working on vaccines for other bacterial pathogens such as Aeromonas salmonicida, which produces furunculosis, and Piscirickettsia salmonis, a cause of significant farmed salmon mortality.

The team has published a series of discoveries from these pursuits. In July this year, the group revealed how feed-based immunization of lumpfish larvae and juveniles against Vibrio anguillarum was found to be less effective than vaccine injected through the abdominal cavity.

They also isolated a new marine pathogen, Pseudomonas sp. from wild cunner and described its genetic makeup in a paper published in April. The achievement was significant because bacterial diseases, due to natural infections in cunner, have yet to be described.

While scientific investigations and commercial interests have largely homed in on lumpish, the possibilities of cunner remain of interest. There are marked differences between the two species, but as cleaner fish, both have commercial advantages.

Mr. Boyce noted, “lumpfish are very active and like cooler waters, less than 14 degrees C, while cunner love warm waters but go torpid in the winter months. They just hunker down.”

Lumpfish are also faster growing. He said, “A 20-gram lumpfish can be produced in less than a year – six to seven months – whereas a cunner is slow growing and it starts out as a really small egg and has a very difficult larval phase with a low survival rate. So biologically, it’s a much harder species to raise than a lumpfish” said Mr. Boyce.

Still, Dr. Santander points out, “utilization of both species as cleaner fish is the ideal goal.” He said, “cunner are utilized by our industrial partners, but their domestication has not been completed.”

Pursuit of that objective suggests plenty of scope for further cleaner fish research at Memorial and lots of added commercial potential to come.