One of the most talked-about uses of the sea is for raising fish, mollusks, crustaceans, algae, and other edible marine organisms in captivity or semi-captivity. Readers who have heard for years about the importance of fish farming to feed a growing human population can be excused for raising skeptical eyebrows on hearing of it yet again. Although specialized operations for growing seafood have been established in many coastal regions around the world, the industry itself hasn't grown as fast as predicted. Logistical and economic factors combined with pollution and diseases have weighed against the success of many fish farms. But with biotechnology added to the scales, the balance may be tipping the other way.

Asian countries are far in the lead of marine farmers, currently producing 85 percent of the world's annual supply of 21 million tones of cultured aquatic organisms. Other fishing nations are striving to catch up, with the Canadian government, for example, forecasting that aquaculture production will contribute at least a quarter of the total landed value of the nation's fish harvest by the end of the 1990s—a big rise over its 1987 level of only three percent.

In the United States, the aquaculture industry grew during the 1980s with the success of catfish farming, but the cultivation of marine species still languishes. Despite its long coastline, the United States ranks 10th in the world in the value of its aquaculture products. Imports of seafood and seafood products contributed $2.5 billion to the American deficit in 1992, behind only petroleum, automobiles, and electronics. Add to such national short-