Keeping aquaculture environmentally friendly

Washington Watch, August 1998

Beth Baker

With wild fish stocks being depleted around the globe, aquaculture is beginning to gain attention from Washington policymakers. Many hope that fish farming can help fill the huge national appetite for seafood (marine and fresh- water fish and shellfish), as well as give an economic boost to areas where commercial fishing has gone belly-up. Meanwhile, environmentalists are calling attention to the potential hazards posed when aquaculture is pursued in an irresponsible manner.

Globally, aquaculture is booming. Between 1984 and 1994, production increased 250 percent. More than a quarter of the seafood consumed worldwide is raised rather than wild, amounting to more than $36 billion in annual sales. So far, US fish farmers account for only 7 percent of the market, but this may soon change. Fish are now farmed in every state, and aquaculture is the fastest-growing portion of US agriculture.

Still, aquaculture has not exactly been a hot issue in the nation's capital, garnering little of the passionate support given to traditional agricultural interests. "It's a real challenge within the federal government to move issues and opportunities like aquaculture forward," says Meryl C. Broussard, the National Program Leader for Aquaculture within the US Department of Agriculture (USDA). Rather than trying to drum up support for aquaculture as yet another issue vying for attention, Broussard hopes to inject it into ongoing discussions about food safety, environmentally sustainable agriculture, and genome research.

At the federal level, support for aquaculture has been hampered by interagency rivalries. Freshwater species, such as catfish, the current mainstay of US aquaculture, have been seen as the responsibility of USDA, whereas marine species are overseen by the Department of Commerce through agencies such as the National Oceanic and Atmospheric Administration and its National Sea Grant Program. Broussard, who also serves as chairman of the Joint Subcommittee on Aquaculture, the coordinating body for all federal aquaculture programs, hopes to end interagency squabbles. "Let's quit arguing about splitting things based on salinity," he says. "I want us to work together in support of commercial aquaculture development."

To this end, USDA gives roughly $60 million annually toward extramural and intramural aquaculture research. "We're talking about modest investments," says Broussard. "Part of my job is getting the Administration reenergized about this."

The Commerce Department has also come up with a strategic plan to support marine aquaculture. Sea Grant gives roughly $4-5 million to support research and education related to marine and coastal aquaculture.

As aquaculture grows, environmentalists are urging that safeguards be put in place to prevent some of the ecological harm that has occurred as a result of this industry in other countries. A recent report by the Environmental Defense Fund (EDF), Murky Waters: Environmental Effects of Aquaculture in the United States, notes that "potential problems from aquaculture effluents include oxygen depletion in surrounding waters, degradation of benthic ecosystems, and exacerbation of toxic algae blooms."

Other problems associated with aquaculture have been raised by this report and numerous scientific studies. These include harmful effects of pesticides and herbicides used to control aquatic weeds and algae; pressure on wild fish species such as anchovy and herring, which are used in fish meal to feed carnivorous farm-raised stocks; and introduction of exotic species into natural streams when fish escape from aquaculture facilities.

In response to concerns raised by Murky Waters, the US Environmental Protection Agency in May announced that it was considering regulations specifically for aquaculture effluents, as part of EPA's authority under the Clean Water Act. EPA studied this problem in 1977, but no regulations were ever issued, and the agency has not done any recent technical assessment work on aquaculture.

Along with effluent regulations, Murky Waters made many recommendations for "environmentally friendly aquaculture." Among them: less reliance on pesticides, antibiotics, and other chemicals used in aquaculture; substituting other kinds of protein for fish meal; raising fish in tanks and other enclosed systems to reduce pollution in natural waters; and releasing effluents into vegetable beds as fertilizer.

Heightened environmental awareness and a sounder regulatory structure will likely prevent the US aquaculture industry from pursuing the destructive course followed in other countries. "The aquaculture community in this country recognizes those problems, and we have the regulatory structure in place to deal with them," says USDA's Broussard.

Rebecca Goldburg, senior scientist for EDF and coauthor of Murky Waters, notes that even the industry publication The Catfish Journal called the environmental report "well-researched and thorough." This acceptance bodes well for the future of aquaculture. As the EDF report concludes: "aquaculture need not be a polluting industry. A variety of strategies and technologies are now available to make fish farming environmentally sound."

Beth Baker is a freelance science writer based in Takoma Park, Maryland.

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