Guiding Sustainable Marine Aquaculture

shores. Aquaculture—the farming of fish, shellfish, or aquatic plants—has grown rapidly over the past several decades, and that growth is accelerating. Today, some 4,000 aquaculture enterprises in the United States, most of them small to mid-size, supply Americans with Atlantic salmon, hard clams, oysters, shrimp, and nearly all the catfish and trout we eat. As the industry matures, it holds both great promise and great risk. It holds great promise because demand for seafood is rising, yet the total global wild fisheries catch has leveled out since the mid1990s as fish stocks have become depleted. In the U.S., 30 percent of the known wild fishery stocks are already overfished or in the process of being depleted through overfishing. Aquaculture represents another source of seafood to boost the fish supply. Although the majority of aquaculture operations raise freshwater species, our work focused on marine species. Some forms of aquaculture, such as mollusk farming, may aid the environment. Because mollusks, such as clams and oysters, filter large volumes of water, they can help to restore marine ecosystems polluted with nutrients and an overabundance of phytoplankton. The industry is also a source of new jobs. During a site visit in Florida, the Commission learned about a job-retraining program that redirects displaced gillnet fishermen into hard clam aquaculture. But despite this promise, marine aquaculture poses significant risks (Figure One, page 74). Farmed fish that escape their pens may pose biological risks to wild populations. Improper facility design, siting, and operation can reduce water quality, damage the physical habitat, and harm wild populations in a variety of ways. Different species and production systems present different challenges and risks, complicating management. This combination of promise and risk has made marine aquaculture an important focus of the Commission’s work. Because the aquaculture industry is still young and relatively small, there is time and opportunity for it to develop in an ecologically sound way. If we are to prevent, minimize, and mitigate the risks, we must develop a coherent policy framework for the industry.