Beasts built of muscle and cunning, some weighing thousands of pounds, cleave the water. Huge nets, giant floating cages, enclose the animals in the open ocean. Fattened on mackerel and herring for years, the life of a farmed bluefin tuna seems cushy — until it’s flash frozen and shipped to Tokyo for auction. Despite aquaculture’s dirty and ecologically destructive image, responsible and innovative fish farming is a crucial means of preserving wild fish.

America needs to refine and expand its aquaculture operations in order to meet growing world demand for fish, safeguard our food system and preserve wild fish stocks. New techniques hold promise that aquaculture in the 21st century will be a safe, highly productive and delicious industry.

Many world fish stocks are depleted or depleting rapidly. European overfishing of Atlantic bluefin tuna, for instance, has reduced stocks to dangerously low levels. The fish migrate across the breadth of the North Atlantic, rendering the conservationist measures instituted by the United States essentially worthless. Hydroelectric dams trap Pacific salmon as they swim upstream to spawn, decimating their numbers.

What to do? Aquaculture offers the solution to declining fish stocks. Using enormous closed-containment ocean tanks pioneered in British Columbia, American fisheries can farm salmon, Gulf of Mexico fish and crustaceans and even the mighty Atlantic bluefin. Such tanks feature pump-driven solid waste capture systems to eliminate ocean pollution and curb disease. Strain on wild fish stocks will lessen as greater quantities of farmed fish enter the market, allowing the government to impose genuinely conservationist catch quotas. Such ocean tanks are considerably more cost-effective than their landed counterparts.

Although the fishing industry will initially cry foul as thousands of watermen are put out of work, their labor can be transferred to the newly established farms. In this way, long-term job loss is not a concern. Unfortunately, farmed carnivorous fish such as tuna and salmon consume large quantities of smaller fish, such as sardines and mackerel, in the farming process. Intelligent quotas for these fish will ensure that the wild stocks remain healthy.

Domestic demand for farmed fish is already substantial, yet international demand will drive the aquaculture industry to new heights. Global fish consumption has doubled since 1973, and 90 percent of this increase has been in developing countries. As these emerging economies over-exploit and destroy their own wild fish stocks (as they almost certainly will), American farmed fish will be needed to feed their growing middle classes. This demand will help resuscitate the American economy without sacrificing the environment.

Some observers object that farmed fish contain the carcinogenic toxins PCB and dioxin, albeit in low levels. This minor toxicity, however, isn’t as dangerous as the mercury contamination found in many wild fish: farmed fish is already the healthier choice in some cases. The aquaculture industry can eventually address its toxicity problems through technical innovation driven by market demand. Just as the British Columbian tanks developed advanced waste and toxin removal systems, consumer demand for uncontaminated fish will drive the development of cleaner and safer farming technology.

Food security is directly linked to aquaculture. Currently, the United States imports 80 percent of all domestically consumed seafood — this practice grows our mammoth trade deficit and exposes our food system to contaminants. Illness from tainted Chinese and Southeast Asian shrimp is a recurring problem. As such, a large domestic farming industry will shrink demand for contaminated seafood and boost domestic output, both of which are crucial to maintaining American economic power.

The missing piece of this puzzle is President Obama: with strict government catch quotas and aquaculture development incentives, fish farming can reel in big rewards.