Aquaculture: satisfying the global appetite.

Three thousand years ago, farmers in China began growing fish in freshwater ponds and a thousand years later began cultivating mollusks along coastlines. For centuries, aquaculture—the farming of fish, shellfish, and aquatic plants—remained mostly a small-scale subsistence activity providing relatively low yields. But during the past few decades, aquatic farming has abruptly undergone a startling transformation. It is now the fastest-growing food production system worldwide. Thirty years from now, experts say, it will provide the largest source of fish and shellfish for human consumption. The revolution in aquaculture accelerated rapidly during the late 1970s, due primarily to two factors. First, as human populations began to skyrocket, experts worried that many hundreds of millions of people could suffer malnutrition. Thus, international agencies such as the World Bank began encouraging aquaculture in developing countries as a method of providing food for the poor and promoting economic development. Second, around this same time China initiated a series of economic reforms to encourage aquaculture. Modern fish farming probably arrived just in time. During the last quarter of the twentieth century, the worldwide human population ballooned from 4 billion to 6 billion. Most of this growth occurred in developing countries. Meanwhile, wild fish harvests were unable to keep up with increasing demand. In the 1970s