Fuss over Farming Fish
Article #984
by Carla Helfferich
This article is provided as a public service by the Geophysical Institute, University of Alaska Fairbanks, in cooperation with the UAF research community. Carla Helfferich is a science writer at the Institute.
The right of Alaska's salmon to live free was one of the battles engaging Alaska's legislators during the past session--or so the debates over fish farming might have seemed to someone catching only the occasional headline or sound bite. Legislative action killed possible salmon farms for now, but some Alaskans are still puzzled over the fuss.
Theoretically, the idea seems sound. Instead of letting young hatchery-produced salmon run away to sea, they are raised in big floating pens. Safe from natural predators and offshore factory ships, they are fed and tended in a protected patch of sea. The eventual result is a living for the fish farmer and a few hired hands and a better supply of affordable and good-quality seafood for consumers.
Of course, problems appear once fish farming gets past the theory stage. Early this year, Science magazine gave space to some controversies about the industry in Washington state that echoed--and perhaps clarified--the arguments in Alaska.
The business is not brand new. The Japanese have reared salmon in floating pens for decades; Norway and British Columbia saw their fish-farming businesses boom during the 1980s. Those track records were cited by salmon farm advocates, who point out Alaska's need to capture a market share for this kind of seafood.
Opponents argue that the business is too risky. Typical Puget Sound salmon farms concentrate 50,000 to 100,000 fish in a two-acre space. A farm that size produces as much organic waste in a year as does a town of 10,000 people. Alaska's waters are still very clean, but how many such pollution point sources would it take to ruin that? What about the health of bottom-dwelling organisms forced to live under an underwater rain of fishy sewage?
Furthermore, uneaten food and fish wastes are high-nitrogen pollutants--potential fertilizer for toxic algal blooms. Though there's no hard evidence that salmon farms have caused eruptions of deadly algae, toxic blooms have driven some Canadian fish farms into bankruptcy. And, reportedly, the largest maritime action ever launched in Norway was the towing of salmon pens away from a slimy mass of toxic algae.
Imported stock could bring imported diseases, which might spread into the free-ranging salmon populations. Fish farming opponents noted the mysterious 1989 outbreak of a deadly disease in two Pacific Coast salmon hatcheries: viral hemorrhagic septicemia had never been seen before in North America. Again, no hard evidence links the appearance of the disease to salmon farming, but the nervous drew their own conclusions from the fact that Scandinavian stocks of Atlantic salmon are the preferred source for pen-reared fish.
Whenever animals live crowded together, risk of disease increases. Just as feed-lot operators provide steers with antibiotic-laced grain, salmon farmers spike their fish chow with drugs to prevent or treat outbreaks of bacterial diseases. That can promote growth of strains of antibiotic-resistant bacteria, and not just in the pens. Resistant organisms have been found near Japanese fish farms, and the antibiotics themselves have been found months later in sediments underlying the farms. The salmon farms thus could lead to super-tough strains of the diseases already present in North Pacific waters.
In Washington, these concerns led to an unlikely alliance among fishermen worried about competition and potential fishery damage, environmentalists, and owners of waterfront property (who were as much concerned about their views being spoiled as about water quality or sport fishing). Responding to those pressures, the state commissioned University of Washington researchers to study farm effects.
The scientists suggested using native rather than imported salmon eggs for farm stock. They also recommended siting pens in areas of high current flow, in effect falling back on the saying, "The solution to pollution is dilution. " That was not enough for the Sierra Club and the Environmental Protection Agency, who have pressured the state to require discharge permits for the farms under the Clean Water Act.
The fuss continues in Puget Sound, but the 13 salmon farms now operating there continue their annual harvest of several thousand tons of fish. Washington state officials still back the idea of continuing the farms and adding more; Science magazine quotes Judith Freeman, of that state's Department of Fisheries, as saying when hard facts do not exist, "all you can do is talk to the researchers who know the most about the area." The state thinks it's done that.
That absence of hard facts would trouble most researchers I know. It may be just as well that Alaskans wait and watch before we add salmon farms to our short list of potential business opportunities.
|
|
