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Can wild and farmed fish co-exist?

New study cautions against relying too heavily on aquaculture to service seafood markets
UBC fisheries economist Rashid Sumaila: “We’ve got to rebuild and take good care of our wild fish, and then when we do sustainable aquaculture, together, hopefully we’ll be able to meet our demand for fish."

The United Nations and World Wildlife Fund have put great stock in aquaculture as an environmentally sustainable way to feed a growing global population, which last week officially topped eight billion.

But a new study led by a University of British Columbia (UBC) fisheries economist cautions against being overly optimistic about aquaculture, and suggests that an over-reliance on it could detract from the imperative of doing a better job of managing wild-capture fisheries.

It notes that aquaculture growth has plateaued and that production of some farmed species has declined.

“We show relevant evidence suggesting that aquaculture growth rates in all the cases studied have already reached their peak and have begun declining,” notes the study, which was published in Frontiers in Marine Science. “Our analysis suggests that Atlantic salmon … is the species with the highest drop in growth rate in the world.”

That is no surprise, given that environmentalists have waged a two-decades long campaign against open-net Atlantic salmon farming. With the removal of open-net salmon farms from the Discovery Islands, they have succeeded in shutting down about a quarter of B.C.’s salmon farms, and last week they marked a victory in Washington state.

There, the Washington Department of Natural Resources announced the cancellation of the last two leases Cooke Aquaculture has for open-net steelhead farms, which ends open-net fish farming in Washington.

Anti-fish-farm activists have cheered the decision, and hope it informs the still evolving policies of Fisheries and Oceans Minister Joyce Murray, who this fall conducted consultations on salmon farm transitioning in B.C.

But environmentalists opposed to fish farming now worry that Murray has modified her strategy, shifting from an all-out phase out of open-net fish farms to more of a harm-reduction approach.

When Murray’s predecessor, Bernadette Jordan, was given her marching orders by the prime minister, her mandate was to “create a responsible plan to transition from open net-pen salmon farming in coastal British Columbia waters by 2025 and begin work to introduce Canada’s first-ever Aquaculture Act.”

In recent round tables that Murray held with environmentalists, First Nations and the aquaculture industry, participants learned that the terms of her mandate had been modified.

The plan for salmon farms in B.C. is now “to progressively minimize or eliminate the interactions between farmed and wild salmon,” according to round-table participants. That may leave the door open to hybrid systems and semi-closed containment, which environmentalists consider half measures.

The biggest concern with open-net fish farms is that they can concentrate and amplify disease and sea lice and transmit them to wild salmon, although Murray’s scientists have said these farms pose a “minimal risk” to wild salmon.

Karen Wristen, executive director of Living Oceans, fears Murray’s plan now leaves open the opportunity for open-net fish farming post-2025 using hybrid and semi-closed containment systems.

She recently wrote Lousy Choices, a report that concluded none of these systems really address the fundamental concern of exposing wild fish to pathogens from fish farms.

“If the technology existed that would permit industrial-scale salmon farming to take place safely in the same waters required to support wild salmon, the debate about salmon farming would be over,” the report states. “But that technology does not exist.”

Nor does Wristen put much faith in new open ocean systems that have been developed in Norway. These large fish pens are placed further out to sea to minimize exposure to wild fish. 

China, which accounts for 60 per cent of the world’s aquaculture production, is now getting in on that game. In June, China harvested its first batch of Atlantic salmon from the Deep Blue Number-1 open ocean system in the Yellow Sea.

“Any place they would put them on our coast, if they are going to anchor them, would be on the Continental Shelf,” Wristen told BIV. “And I want to assure you there is no place on the Continental Shelf that doesn’t have fish. The question is whose fishing ground are you going to disrupt?”

Environmentalists say the only safe way to farm salmon is on land. While recirculating aquaculture systems (RAS) technology has developed to the point where large volumes of finfish can be raised on land, the economics have proven challenging, especially for salmon.

Atlantic Sapphire ASA (OTCMKTS:AASZF) has invested more than US$300 million in a large land-based system in Florida. Since its first harvest of Atlantic salmon in 2020, it has suffered a number of mass fish die-offs and continues to operate at a loss, posting a net loss of US$14.5 million for the first half of 2022.

Rashid Sumaila, a UBC fisheries economist, and lead author of the recent study on aquaculture, thinks land-based systems would be an ideal alternative to open-net fish farming, if the economics could be made to work.

“It’s a big challenge to make the economics work,” he conceded. “And that is a big barrier. I think land-based, if we can make it economically feasible, could be a nice way to add fish, salmon, for people in B.C. and Canada.”

Ruth Salmon, executive director for the BC Salmon Farmers Association, said the industry is investing in new technology and practices to reduce the impacts salmon farming may have on wild fish, but added that it needs time and investor confidence to refine the technology.

“A lot of things that we’ve been thinking about do need time for trials,” she said. “That’s one of our issues with the speed at which Minister Murray wants the transition to go.”

Murray is aiming to have a plan for B.C. fish farming in 2023 with new regulations to be implemented in 2024. There is no similar plan for fish farming in Atlantic Canada.

“You really need investor confidence to invest the dollars and the time necessary to do this,” Salmon said. “There’s a lot of really interesting ideas. But we do need time and investment to trial them.”

Wild fisheries contributed 51 per cent and aquaculture contributed 49 per cent to the world’s seafood harvest in 2021, according to the United Nations.

Like any new industry, aquaculture enjoyed a great growth spurt between the 1980s and 2000s, but has since plateaued, Sumaila found in his study.

“We see this pattern almost everywhere: They grow and they tapper off,” he told BIV. “It can grow, but much slower than people expect. To me what it means, we really need to do all we can to sustain and manage our wild fisheries so the two together can work up.”

It’s estimated that 80 per cent to 90 per cent  of the world’s wild fish stocks are already harvested at a maximum sustainable yield. In B.C., the commercial sockeye salmon fishery is virtually dead, thanks to a trend of Pacific salmon abundance shifting increasingly north, likely as a result of climate change.

This year, 6.8 million sockeye returned to the Fraser River system – three million short of the pre-season forecast, according to the Pacific Salmon Commission. Canadian commercial fishermen were allowed to catch just 229,000 fish.

In Alaska, meanwhile, commercial fishermen caught 74.8 million salmon (all species) this year, and Bristol Bay shattered records with a massive return of 69.7 million sockeye.

Sumaila doesn’t buy the argument that the world’s oceans have reached the limit of their carrying capacity. He believes there is room to grow wild fisheries.

“There are estimates around the world that fish can come back, provided we haven’t taken up all the habitats,” he said. “There is some percentage increase that we can get from the wild. These species are very resilient, if we give them a chance.”

His main concern is that managing and rebuilding wild stocks of fish could get ignored if too much hope is pinned on aquaculture.

“We’ve got to rebuild and take good care of our wild fish, and then when we do sustainable aquaculture, together, hopefully we’ll be able to meet our demand for fish,” he said. “I think we just need to find a balance to make our wild and farmed fish to be sustainable.” 

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