Above: A marine donut onsite in Molde, Norway undergoing functional testing.
The Bluegreen Group, a Norwegian-based microplastic firm, has created a self-contained aquaculture system known as the marine donut that may be the solution to many of Atlantic Canada’s aquaculture problems.
The design by Bluegreen Group takes its name from its circular, donut-like shape. The structure is made of high-density polyethylene and is 60 feet in height, 180 feet in diameter, 22,000 cubic metres in volume, can house up to 1.1 million salmon and acts as a barrier to the ocean that keeps the fish within them from getting out and risks to fish like sea lice, predators and ocean-born infections from getting in.
This closed containment system, according to Mark Lane, the director of Bluegreen Canada Inc., can be configured to all types of aquaculture methodology, from operating as a post-smolt facility to the growing of ready-to-slaughter fish.
“We’re a turnkey for whatever the farmer needs. What I tell people is we’re an additional tool for farmers to use as they see fit,” said Lane. “So, it could be used to produce post-smolt. For example, taking fish at 60 grams and then growing them over a period of four months to 1–1.1 kilos, then putting them in that pen in the ocean, which is what I think most people would be interested in in Canada in the short term. But you can also put them in at 60 grams and grow them to market size if you want. Or you could put them in at 60 grams, grow them to 1.1 kilos and then put them in the offshore.”
According to Lane, the cost of sea lice infestation on salmon farms is roughly $1–1.50 USD per kilogram of fish when accounting for treatment measures and mortality. Newfoundland and Labrador aquaculture farms also suffer from outbreaks of infectious salmon anemia.
The marine donut reportedly solves these issues by taking the water used in the facility from a depth of 40 metres, which is below the habitat of sea lice. The water is then filtered and UV-treated, killing any remaining pathogens in the water. Given that the water is taken from depth and held in closed containment, the water temperature of the marine donut also remains more consistent throughout the year.
“You bring it in, you’re filtering it, you’re treating it with UV. So, hypothetically, you should not take any sea lice and kill any pathogens that may exist naturally in the environment,” said Lane.
The interior of the marine donut provides a continuous circulation of water which not only gives the captive fish consistent exercise but allows for less food waste for aquaculture facilities. Lane said that the lack of food waste will allow the donut to grow fish in a more cost-efficient manner than a net pen.
“Food conversion ratio is, ideally, if you put in a kilogram of feed, you get a kilogram of growth. That would be a 1:1 ratio. We think we can do it at a 0.8; the reason being is because the food circulates in the system,” said Lane. “If you put feed into a net pen, some of it could drift outside or some of it could sink through the bottom. In our modelling, because it’s circulating a toros shape, you have multiple opportunities for a pellet to be eaten.”
Lane and Bluegreen Group are excited to attempt to bring the reported benefits of their technology to the ever-growing Atlantic Canadian aquaculture market. Lane said that getting the marine donut up and running off the coast of Newfoundland and Labrador would be the ultimate test of the design’s capabilities.
“Newfoundland, I think personally, is one of the most difficult places to live on Earth, let alone grow fish,” said Lane. “If we can prove that this donut is functional and does what I think it will do in the ocean environment of Newfoundland, I’m convinced it’s going to work anywhere.”
While Bluegreen Group has yet to get any physical presence in the province, Lane has submitted an environmental impact assessment to the provincial government and has gotten approval for the marine donut to be built. He and his team are looking to either Argentia or Harbour Breton as the location for the very first marine donut site after they raise the necessary funding to begin the project.
“We’re working with industry and some other local partners to secure some additional financing, because we’re not looking for government to foot the entire bill by no stretch of the imagination. But what we are looking at is some level of de-risking our investment, and that could be through longer-term licenses, for example,” said Lane.
“In British Columbia, licenses are two years. This thing costs millions of dollars and according to your financial plan, need to amortize it over 10–20 years. A two-year license is no good, there’s no assurance in that.”
In terms of the initial input cost of building a marine donut, Bluegreen Group is still working out the exact cost. Lane claims that while the input cost would be higher than a traditional net pen, the reduction in operational costs in dealing with sea lice, food waste and disease would make up for the high cost of a marine donut in the long term.
Bluegreen is looking to set up a collaborative cooperation with local fish farmers to find a group to operate their planned aquaculture facility to provide proof-of-concept within the province. Preliminary engineering has been done for the fabrication site, and Lane hopes to have all financing secured by December 31, 2023.
“We can start construction by April or May of 2024, which is ambitious, but I think it’s doable,” said Lane. “Hopefully we see a donut in the ocean in 2025.”
