Should you eat farmed fish? It's complicated
Should you eat farmed fish? It's complicated
For environmentalists, some food production and consumption choices are simple. Eating less red meat is better than eating more. Beef and cheese have bigger climate impacts than turkey and eggs. Fruits and vegetables in season likely have a smaller footprint than strawberries in the wintertime.
The issue of farmed fish, however, is complicated -- because it includes many species of fish that are farmed using different methods in different places. Done right, aquaculture is an environmentally-friendly, sustainable way to produce healthy protein. But done wrong fish farming generates pollution, relies on antibiotics and threatens ocean ecosystems.
So what’s a conscious consumer to do? And, for that matter, how are responsible retailers supposed to navigate the world of aquaculture?
Help is on the way, say experts at the recent Cooking for Solutions event, a great two-day gathering about food and sustainability organized by the Monterey Bay Aquarium. The aquarium is a great place to visit, of course, but it’s also a force for sustainable food, with a focus on seafood and oceans.
Roughly half the world’s fish supply is farmed – and some environmentalists are excited by the potential of aquaculture to heal marine ecosystems that have been battered by overfishing. “Aquaculture’s big,” said Jose Villalon, a fisheries biologist who leads the aquaculture program at the World Wildlife Fund (WWF). “It’s the fastest growing food industry in the world. It’s not a trend. It’s here to stay.” Villalon notes that aquaculture has been growing at about nine percent a year for at least a decade, and that fish farming can become one of the most sustainable sources of healthy food.
Tom Pickerell, a research scientist at the aquarium, agrees. “We will not be able to feed the world in the future without aquaculture,” he said. “There has to be a blue revolution of sustainable aquaculture.”
What’s needed, these experts say, are metrics and standards -- to help motivated buyers figure out which farmed fish to select and which to avoid. This, of course, is the focus of the Aquarium’s well-known Seafood Watch program, which offers useful guidance but requires a vigilant attitude on the part of consumers. For example, Seafood Watch advises people to avoid imported shrimp farmed in open systems, although shrimp farmed in fully re-circulating systems in the U.S. are rated a “best choice”. Farmed tilapia gets a green light if it comes from the U.S., a yellow light if it comes from Brazil and a red light if it comes from China. Seafood Watch puts its ratings at people’s fingertips, with a handy pocket guide and an iPhone app, and it has a great deal of influence with chefs. But can we really expect consumers to pay attention to the provenance of their fish?
WWF has a different theory of change, Villalon explained. He sits on no fewer than eight “multi-stakeholder roundtables” devoted to different species of seafood. These groups, he hopes, will guide the biggest players in the aquaculture industry: companies that buy seafood in bulk.
“There are billions of consumers,” Villalon said. “There are millions of producers. The stem in the champagne glass is the hundreds of big seafood buyers. Basically what we try to do is encourage the retailer to make the right choices for the consumer.”
To that end, a nonprofit called the Aquaculture Stewardship Council (ASC) will begin certifying farmed seafood this year. The ASC label complements the Marine Stewardship Council (MSC) label, which is used on certified and sustainable, wild caught fish. Both councils are made up of environmentalists, producers and retailers.
Deciding what to measure in aquaculture isn’t simple. One key metric, as with any form of food production, is efficiency; in this case, how much other fish and other foods it takes to grow farmed fish. In an influential paper published in Nature back in 2000, Stanford economist Rosamond Naylor and her colleagues found it took three pounds of wild fish — in the form of fish meal — to provide enough food to grow one pound of farmed salmon. That’s inefficient, obviously. “The growing aquaculture industry cannot continue to rely on finite stocks of wild caught fish,” they wrote. That’s one reason why farmed salmon has a bad reputation.
By contrast, farmed mussels and oysters don’t require any feed at all, and tilapia, a popular farmed species, can be fed plants. Feed ratios have come down for salmon, shrimp and other species in recent years -- as fish farmers, like all farmers, try to reduce their input costs.
On the whole, aquaculture is “ecologically efficient,” said Daniel Benetti, a professor and director of aquaculture research at the University of Miami. The industry takes 15 million metric tons of forage fish from the ocean and produces 60 million tons of fish a year.
Innovation should drive further improvement. Experts on a Cooking for Solutions panel spoke favorably about IMTA (integrated multi-trophic aquaculture) which I wrote about here and here. Australis, which farms barramundi in western Massachusetts, is another promising aquaculture firm. (See my blogpost, Josh Goldman’s amazing fish story.) Aquaculture is only going to grow bigger, so there’s good reason to try to get it right.