Known as offshore fish farms, these structures have been popping up around the world in recent years. Their proliferation in open waters, often several miles offshore, has sparked heated debate: some see them as the next frontier for sustainable production of fish like Atlantic salmon, sea bass and cobia. Others describe them as “factory farming of the sea”. What almost everyone can agree on is that these deepwater farms are poised to grow in the coming years. Between 1961 and 2017, global demand for fish grew an average of 3.1% per year, leaving companies scrambling. “Aquaculture is the fastest growing form of food production in the world,” says Robert Jones, the Nature Conservancy’s global head of aquaculture. “And we are at the beginning of this industry. Now is the chance to influence where it goes.” A fish farm off the coast of the Moroccan city of M’diq, October 2019. Fishermen hope that aquaculture will secure their future as fish stocks dwindle. Photo: Fadel Senna/AFP/Getty Images The Nature Conservancy has long viewed offshore farms as a potential game changer for fish production, albeit one with enormous challenges. “It’s growing rapidly around the world and it’s an opportunity for conservation,” Jones said. “But it can also be at the expense of the environment.” What appeals to the organization is the potential for farms to reduce pressure on wild fish populations. In 1974, about 10% of fish stocks in the world’s marine fisheries were being depleted too quickly for species to be replaced, according to the UN’s Food and Agriculture Organization. By 2017, this figure had risen to 34%. Deep-sea offshore farm locations are also seen as an advantage because stronger currents can dilute waste and avoid coastal degradation often seen in fish farms located in bays and estuaries. Others argue that environmental concerns outweigh the potential benefits. Last month, a coalition of nine U.S. groups, including marine conservation organizations and the Quinault Indian Nation, filed a notice of intent to sue the U.S. Army Corps over its decision to issue a national permit that could open the way for fish aquaculture facilities to be built in state and federal waters. It’s been touted as a solution to overfishing, but to feed the fish, you have to get more wild fish Meredith Stevenson, Center for Food Safety The coalition warns that blanket approval was granted without fully considering the impact the farms could have on threatened and endangered species. The farms are often accompanied by an increase in marine traffic, the groups say, which could increase the risk of ship strikes, particularly as animals are drawn to the site by the scent of food. They list a number of additional concerns, from concerns that the constant flow of water through the farms will release animal feed, antibiotics and feces into open waters to the risk of farmed fish escaping and threatening local ecosystems. “We see these as animal factories in the sea,” says Meredith Stevenson, an attorney for the Center for Food Safety, one of the groups behind the legal challenge. “It’s the wild west out there.” There is also the risk that farms rely on small, wild fish for food. “It’s branded as a solution to overfishing, but to feed the fish, you have to get more wild fish,” Stevenson adds. Fish and shellfish farms are growing at a breakneck pace around the world, especially in China. Between 1990 and 2018, fish farming increased by 527%, according to the UN’s Food and Agriculture Organization. Offshore fish farming ranks among the industry’s riskiest bets. The enclosures must be built to withstand the high seas, from meter-high waves to wild currents, while their remote locations mean any problems are usually more time-consuming and expensive to fix. The increased risk of bad weather means that even routine operations have to be postponed from time to time. Even so, investors have poured tens of millions into the industry. Virginia-based Forever Oceans has raised nearly $120 million from investors, according to Bloomberg, while a venture fund linked to Walmart heiress Christy Walton has backed half a dozen initiatives related to open ocean aquaculture. For many, the lure is the promise of sustainable fish production. “Our fish can feed the world and restore our oceans,” is how Forever Oceans describes its mission. Hawaii-based Ocean Era, which has an offshore farm near Mexico, says its goal is to “mitigate humanity’s footprint on the oceans.” Blue Ocean Mariculture, which raises fish in underwater tanks near Hawaii, says it will “produce the best-tasting fish without harming the environment.” Bluefin tuna in an offshore facility near L’Ametlla de Mar, Spain. Tuna farmed offshore were found to have reduced mortality compared to those farmed closer to shore. Photo: Pau Barrena/AFP/Getty Images Studies delving into farms have produced mixed results. A 2019 study that collected water samples near submerged fish cages off the coast of Panama concluded that, when properly located, offshore farms can produce a relatively small pollution footprint. A 2011 study comparing more than 15,000 tons of southern redfish farmed offshore and closer to shore found that those farmed offshore had reduced mortality and were less susceptible to sea lice. However, a 2020 outlook published in Nature argued that the high costs associated with offshore farming meant these products would be out of reach for low-income consumers, suggesting limited scope for alleviating food insecurity. The researchers also argued that the fuel consumed by boats heading to and from the farms could jeopardize environmental claims. Overall, the evidence to support offshore fish farms remains thin, says Jim Walsh, policy director at Food & Water Watch. “The development of these fish farms is far from being 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 sustainably in our oceans.” There is already a lack of oversight of the fishing industry, Walsh says. “To think that all of a sudden we’re going to have a regulatory regime that’s going to step in and monitor these factory fish farms is ridiculous.” 40% of arable land is already devoted to food production… there must be new sources Steve Gaines, marine ecologist A better option may be land-based tanks, where fish are raised 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 changed when he encountered forecasts suggesting that demand for food could double by 2050 as the world’s population grows and becomes wealthier. “My reaction was, ‘Oh my God, how are we going to produce this much food?’ says Gaines. “40% of arable land is already devoted to food production … there must be new sources.” Aerial view of fish in the Saronic Gulf, Greece. Fish farming could provide an answer to the problem of food security. Photo: Miloš Bičanski/Getty Images What he landed on was fish farming. “Although there are many problems – as there are with any form of food production – it is by far the one with the greatest potential for expansion.” As companies experiment with fish feed derived from products such as insect protein or bacteria-based protein in order to minimize pressure on wild-caught fish stocks, aquaculture could result in a smaller environmental footprint compared to the production of other forms of livestock. protein. He says. It makes perfect sense, Gaines says, since most of the fish we eat are cold-blooded, don’t have to fight gravity, and have smaller skeletons, which means they’re much more efficient at turning food into food. And then there’s the vertical nature of fish farms. “The surface area to produce a given amount of food is also dramatically smaller if you can grow them in a wet 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 largely depends on the types of species being bred. in fish densities that are low enough to prevent disease from multiplying; and in locations that have high enough water flows to absorb the waste produced by farms. “There are obvious ways you can do it badly,” he concludes. “But it can be done well, and the technology is there to do it well. It’s really important – it has a lot of implications for the next 30 years and more on the planet.”
