(3 of 4)
Farmers have had thousands of years to improve agricultural methods and breed domesticated animals like cows and pigs with maximum efficiency. And industrial agriculture can be polluting: the dead zone in the Gulf of Mexico is due largely to fertilizer runoff from the Midwest. Modern aquaculture is just a few decades old, and as producers have become more experienced, they've cut down on pollution and bred more-efficient fish. Many environmental groups that once opposed aquaculture now seek to work with the industry. The World Wildlife Fund (WWF) is leading the way in this effort, helping develop sustainability standards for farmed species. "Our industry is under a lot of scrutiny, and we're doing our best to alleviate those worries," says Nell Halse of Cooke Aquaculture, a major producer in Canada and the U.S.
And no matter how much room the industry has for improvement, aquaculture usually puts less stress on the environment and requires less caloric input to yield a pound of protein than meat production. Part of that is simply a result of biomechanics and metabolism. Unlike land animals raised for food, fish are cold-blooded and live in the water, which means less of their feed is wasted from our point of view being burned as energy to keep warm or to build bone. Fish farmers had the bad luck to come along after industrial meat production was well established, and the new guy on the block gets more scrutiny. "We have to address the environmental and social issues," says Jose Villalon, director of the WWF's aquaculture program. "But aquaculture is a good tool to deal with food security."
One way to address those issues is to build an aquacultural system that mimics nature, in which the waste produced by farmed fish is put to use. Thierry Chopin, a biologist at the University of New Brunswick, wants to take advantage of that principle with his integrated multitrophic aquaculture (IMTA). In an IMTA loop, species like salmon and shrimp are raised less densely than in conventional aquaculture, together with seaweed and shellfish like mussels. The waste from the farmed species fertilizes the seaweed, which can be harvested for use in fish feed. The mussels, which are filter feeders, can gobble waste in the water, preventing pollution from building up. The result is more biomass and less waste just as nature intended. "If it functions as an ecosystem does," says Chopin, "then it functions right."
Even an aquacultural system more in tune with nature still faces essential challenges, including the feed-ratio problem. When producers began raising fish intensively, they picked species that people like to eat: salmon and sea bass. But those species are high on the food chain, and raising them on a farm is a bit like trying to domesticate tigers. The aquaculture industry has gotten better at replacing fish meal with plant-based feed, but not fast enough. You're not feeding the world sustainably if you need to remove the base of the marine food chain to do it. "The question of what the fish will eat is central to aquaculture," says Australis' Goldman. "We can't grow on the back of small forage fish."
A Fish and a Dream
The answer might be simply to find a better fish, one more suited to farming. This is exactly what Goldman set out to do. He got into aquaculture in the 1980s as a college student and had a tilapia-farming operation for a few years. But while tilapia are more sustainable than many other fish because they're vegetarians, they lack the high amounts of omega-3 oils that make salmon so heart-healthy. Goldman tried striped bass but found them too fussy to raise. It wasn't until a chance encounter with an Australian entrepreneur that he found his dream fish: the barramundi.
As a farmed species, the barramundi is just about perfect. It can survive in a wide variety of environments and lays eggs frequently. It has a flexible diet, and much like its fellow Australians, it is laid-back by nature, so it can endure the rigors of farming. Goldman launched Australis in Turners Falls in 2004 and was producing barramundi commercially by 2005. The fish is rich in omega-3 oils; Dr. Oz named it one of his top superfoods in 2010. Less than 20% of the barramundi's feed at Australis comes from fish meal and fish oil a better percentage than for many farmed salmon, which can require as much as 50% of their feed from fish meal. The Turners Falls operation is an indoor, closed recirculating system, so there's little waste, little risk of disease and no threat that the barramundi will escape into the wild. Plus, barramundi tastes good, with the flaky mouthfeel of the better-known sea bass. Goldman's real challenge is convincing Americans with their appetite for shrimp, tuna and salmon that they should eat an unfamiliar Australian fish. "Selling it as sustainable helps," he says. "But once they try it, people like it."
Australis' barramundi has become so popular, in fact, that Goldman has expanded production but not in Massachusetts. While the closed recirculating system he uses in Turners Falls is an environmentalist's dream, Goldman eventually wanted to reach a larger market at a lower cost, a step that he decided required an outdoor operation on the central coast of Vietnam. That branch, where barramundi are raised in sea cages in a protected bay, isn't quite as green as Turners Falls, but it's cheaper.