March 2015 Issue

What is Aquaculture?

Aquaculture, or “fish farming,” is the process of breeding, raising, and harvesting animals in all types of water environments, such as ponds, rivers, lakes and oceans. Although aquaculture may seem new, fish farming has been going on since as early as 6000 BC, when indigenous populations created channels to raise fish. Today, aquaculture provides the world with 148 million tons of fish per year, according to the Food and Agriculture Association. The U.S. is a minor global aquaculture producer; most of it comes from China (62 percent), followed by India, Vietnam, Indonesia, Bangladesh, Norway, Thailand, Egypt, Chile, Myanmar, the Philippines, Brazil, Japan, and South Korea. About 600 types of aquatic species are raised in farms around the world, but the leading import to the U.S. is shrimp, followed by Atlantic salmon, tilapia, and shellfish (scallops, mussels, clams, and oysters.)

Diving Into Farmed Fish

Aquaculture may be a promising solution for feeding seafood to a hungry planet. EN guides you to the best catch.

“Depending on where you live, there is no industrial hunting anymore,” says Aaron McNevin, Director of Aquaculture for the World Wildlife Fund (WWF,) a global nonprofit conservation organization. Large buffalo herds no longer roam the prairie, and wild fish populations, many of which are threatened, may be going the way of the buffalo.

Photo: Thinkstock

Is Your Fish Farmed?

According to the FDA, fish labeling should include the country of origin, and indicate if it’s farmed or wild. “About 70 percent of the salmon, 100 percent of the tilapia, and 90 percent of the shrimp consumed in the U.S. is farmed,” says McNevin, WWF director of aquaculture.

Feeding fish to a hungry planet. “Wild fish supplies are just not there now. The greatest share—80-85 percent of the wild fish stock—are fished out or are at their capacity,” says McNevin. To top it off, modern fishing techniques can cause damage to oceans beyond overfishing, such as destroying “bycatch” (species caught unintentionally) and damaging the sea floor through trawling.

Thus, aquaculture (fish farming) may help provide enough fish to meet the recommended two servings per week, as suggested by the USDA for optimal health. “Farmed fish are nutritionally equivalent to their wild counterparts,” says Barbara Ruhs, MS, RD, a nutrition consultant for supermarkets.

How sustainable is aquaculture? Many environmental organizations, such as WWF and Monterey Bay Aquarium, recognize that aquaculture holds an important role in supplying seafood to the world. However, they report that many environmental concerns must be addressed in order to create a sustainable aquaculture system, including the following:

- Fish Feed. Feed used to nourish farmed fish utilizes other fish for production, which is a concern. “If you’re using more wild fish to produce farmed fish, you’re not reducing the pressures on the ocean,” says McNevin. However, one-third of all farmed fish, such as oysters, mussels, and scallops, rely completely on food found naturally in their environment, such as plankton. And fish feeding systems are making improvements, including more efficient feeding techniques and greater amounts of plant materials and fish byproducts (not used in human food) used in the feed.

Depleting fresh water supplies to fill aquaculture ponds, as well as polluting waterways, are concerns. Yet, many fish farms have state-of-the-art water systems that recirculate and clean water internally to limit water waste and reduce potential exposure from microorganisms.

- Contaminants. The release of wastes into the waterways is a concern, though many fish farms monitor discharges to limit negative impact. Whether fish are in the open sea or in farms, there’s potential for environmental contaminants, such as PCBs. McNevin says the evidence is conflicting, some studies show less potential to accumulate toxins in farmed conditions vs. wild, and some show the opposite. However, experts stress that the health benefits of eating seafood outweigh potential risks of contaminants.

Shopping for the best farmed fish. The environmental impact of fish farming varies widely, depending on the methods used. “For aquaculture, just like any other farming, there are good producers and bad producers,” says McNevin. Fortunately, certification programs may offer consumers a reliable method of determining if fish is produced sustainably.

Seafood Watch. This Monterey Bay Aquarium program helps consumers choose sustainable seafood—both farmed and wild. Their recommendations include: “Best Choices,” “Good Alternatives,” and “Avoid.” Download the guide or search for specific fish at seafoodwatch.org.

Aquaculture Stewardship Council. After 10 years of roundtable meetings with farmers, retailers, NGOs, and scientists, the WWF established measurable standards for responsibly farmed seafood and co-founded the Aquaculture Stewardship Council (ASC) to manage global standards and certification programs.

Grilled Salmon With Arugula Chimichurri