Researchers at UCLA and UC Santa Barbara want the world to build more fish farms.
There's no use in denying it: The ocean’s wild fish stocks are being depleted. Salmon may go extinct in the next 50 years. Some particularly dour experts think the world’s entire fish supply could run dry by 2048. Overfishing threatens to make seafood a meal of the past. Most people want to keep fish on their plates, but how? Researchers at UCLA and UC Santa Barbara think they may have found a possible solution.
In a study published yesterday in Nature, researchers at the California universities argue that marine aquaculture—fish farms, essentially—could take the pressure off wild fish populations. Rebecca Gentry, one of the study’s authors, recently completed her Ph.D. in aquaculture ecology. She talked to Food & Wine about aquaculture’s potential to transform our oceans.
“0.015 percent of the global ocean area could produce the current total landings [from wild fisheries],” Gentry explained. “Marine aquaculture can be space efficient because it’s three dimensional. It is quite startling when you see how little space it takes.”
If that tiny amount of space could help support fish production, why don't more countries take advantage of the practice? In fact, there is more aquaculture happening in the world that you might think. Gentry explains that half of the seafood we eat today is not caught wild, but farmed. Norway—one of the countries, along with Chile and China, practicing the most aquaculture—has pioneered the farming of salmon. But the majority of aquaculture in use right now is focused on fresh water ponds, lakes, and streams, and has yet to venture out into the oceans.
While Gentry and the team of researchers behind the study don’t advocate for marine aquaculture replacing wild capture fisheries—those fishing boats that net wild fish by the ton—they do believe that many countries have the potential to produce massive amounts of seafood—mollusks like mussels and clams, too, not just fish—if they adopted the practice.
Take Australia. Gentry says that if that country alone started implementing aquaculture, they could potentially produce as many as 24,000,000 tonnes (1 tonne is equal to 2,205 pounds) of fish "if 1 percent of the suitable area in [the] country was developed for low-density marine finfish aquaculture,” according to one figure in the study. The same goes for Indonesia and parts of South America.
Despite that potential upside, there are serious issues standing in the way of a global movement to build more of these farms.
“It’s expensive because you need stronger engineering to withstand the oceans. Feed is a huge issue too,” says Gentry. “It can develop really quickly under the right circumstances, but some countries have been restrictive on it.”
In America, for instance, where fresh water aquaculture is already in place for species like tilapia and catfish, the first marine aquaculture farm for mussels only recently began operations. Why did it take so long for America to catch on to marine aquaculture? Gentry says that a lot of the delay has to do with bureaucratic red tape.
“You have to go through multiple agencies and it’s extremely expensive. They want to preserve the oceans. A lot of early operations had problems with diseases and pollution," Gentry explains. "There’s also the fear that farmed fish escaping into the wild will cause an eco system problem." But she goes on to say that measures are being taken to address those concerns. Farms placed in deeper water, near higher currents that keep the water flowing are better for the health of the fish. And to prevent damage to the cages that could potentially let farmed fish loose into the wild population, including from predators who are hoping to free lunch, engineers are developing cages with anchors to keep them stable, and others that submerge during storms.
And while Gentry warns that aquaculture is “not a panacea,” for the problems of climate change and overfishing, it is one of the fastest growing food production methods in the world right now, and it’s only going to keep growing. The only question that remains is where it will grow first.