Offshore Fish Farms: a Boon or a Curse?

Deep-sea aquaculture is proliferating around the planet, promising to ‘feed the world.’ As recently as January 2022, Forever Oceans—a US-owned company—signed a deal with the Brazilian government to create the world’s largest offshore fish farm in the coastal state of Bahia in north east of Brazil. And a new survey conducted by an American-aquaculture advocacy group called Stronger American Through Seafood (SATS) found that the majority of voters (84%) support establishing a stronger offshore fish farming industry in the US.

Yet many fear the harm this new frontier could wreak on marine life.

Known as offshore fish farms—enclosures that stretch far and wide but from above appear as floating dots scattered across the ocean—these structures have appeared around the world in recent years. Their expansion in open waters, often sitting several miles off coastlines, has sparked heated debate as to whether they can be the next frontier for the sustainable production of fish or “factory farming of the sea”.

The point of agreement, however, lies on the prediction that these deep-sea farms are poised to surge in the coming years. Between 1961 and 2017, global demand for fish grew an average of 3.1% a year, leaving companies scrambling.

“Aquaculture is the fastest growing form of food production in the world,” says Robert Jones, the Nature Conservancy’s global lead for aquaculture. “And we’re at the very beginning of this industry. Now is the chance to influence where it goes.”

The Nature Conservancy has viewed offshore farms for a long time as a potential revolution for fish production, despite some huge challenges for the environment.

On the benefits side of the argument, the farms could unburden pressure on wild fish populations. In 1974, about 10% of the fish stocks in the world’s marine fisheries were being depleted too quickly for species to replace themselves, according to the UN’s Food and Agriculture Organization. By 2017, this proportion had climbed to 34%.

Locations of the deep-sea offshore farms are also seen as beneficial, because stronger currents may thin out waste and avoid the coastal degradation often seen in fish farms located in bays and estuaries.

Others argue that the environmental concerns outweigh any potential benefits. Last month, a coalition of nine groups in the US, including marine conservation organizations and the Quinault Indian Nation, filed a notice of intent to sue the US Army Corps over its decision to issue a nationwide permit that could pave the way for finfish aquaculture facilities to be built in state and federal waters.

The coalition warns that the blanket approval was granted without fully considering the effect farms could have on threatened and endangered species. The farms often cause a rise in marine traffic, the groups say, which could accordingly increase the risk of vessel strikes, for animals are likely to be attracted to the site by the scent of feed.

Additional concerns include worries that the constant flow of water through the farms will let feed, antibiotics and faecal matter into open waters to the risk that farmed fish could escape and threaten local ecosystems.

There’s also the risk that the farms will need to rely on small, wild-caught fish as feed. “It’s branded as a solution to overfishing but, in order to feed the fish, you have to get more wild fish,” adds Meredith Stevenson, an attorney with the Center for Food Safety.

Offshore fish farming ranks among the riskiest bets of the sector, as enclosures need to be built to withstand the open sea, from waves to fierce currents, while their remote locations mean any issues are usually more time-consuming and costly to fix. The greater risk of bad weather means that even routine operations need to be delayed at times.

Nevertheless, investors have poured tens of millions into the sector. For instance, Virginia-based Forever Oceans has raised nearly $120 million from investors, while a venture fund linked to Walmart heiress Christy Walton has backed half a dozen initiatives related to open-ocean aquaculture.

Studies analyzing the deep-sea farms have yielded varied results. A 2019 study that collected water samples near submerged fish cages off the coast of Panama concluded that, when located appropriately, offshore farms can produce a relatively small pollution footprint. A 2011 study comparing more than 15,000 southern bluefin tuna farmed offshore and closer to the coast found those grown offshore had reduced mortality and were less prone to sea lice.

But a 2020 perspective published in Nature argued that the high costs associated with offshore farming meant these products would be inaccessible to low-income consumers, suggesting limited scope in alleviating food insecurity. Researchers also argued that the fuel consumed by boats heading to and from the farms could compromise environmental claims.

Overall, the evidence in support of offshore fish farms remains scant, says Jim Walsh, policy director of Food & Water Watch. “The development of these fish farms is far from studied to an extent that could make us feel confident.” The remote locations, he says, would make it “impossible to effectively regulate factory fish farming in a sustainable way in our oceans”.

There is already a lack of oversight of the fishing industry, Walsh says. “To think that we will, all of a sudden, have a regulatory regime that’s going to step in and monitor these factory fish farms is ridiculous.”

A better alternative may be land-based tanks, where fish are farmed in isolation from the surrounding ecosystem, he says.

Walsh’s view clashes with those who describe offshore fish farming as one of the few realistic options for feeding the planet. Among them is Steve Gaines, dean of the Bren School of Environmental Science and Management at the University of California, Santa Barbara. His perspective shifted after he came across projections suggesting demand for food could double by 2050 as the global population grows and becomes wealthier.

And then there’s the vertical nature of the fish farms. “The surface area to produce a given amount of food is also dramatically less if you can grow them in a liquid environment than on land,” he says. “You can’t stack cows 100 feet high.”

Gaines is quick to list the many caveats of his analysis; it depends heavily on what kinds of species are raised; on fish densities that are low enough to keep diseases from proliferating; and on locations that have high enough water flows to absorb waste generated by the farms.

All in all, it appears that the deep-sea farms and aquaculture have a lot of implications in terms of the next 30 years and more of the planet.

Reference: https://www.theguardian.com/environment/2022/jul/20/offshore-fish-farms-a-new-wave-of-food-production-or-the-wild-west-of-ocean-pollution