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The global seafood haul has more than doubled since 1950, and the sustainable catch limits have already been reached in some species: the American lobster, halibut, haddock, tuna, cod and salmon. French Diplomat Michel Lennuyeaux-Comnene, a spokesman on fisheries policies, says that the seas are being so badly overfished that there may well be "no more fishing" in only 20 years. He warns: "We're literally eating our capital."
But others are not so pessimistic. At present, the seas supply only 13% of the world's animal-protein intake. Fisheries Expert Roland F. Smith of the National Oceanic and Atmospheric Administration (NOAA), believes that protein from the sea could feed 1.5 billion people — almost half the world's population.
Smith notes that the 65 million metric tons of fish caught annually represent only one two-thousandth of the oceans' yearly fish production. One way to squeeze more out of the sea, he suggests, would be to wean people away from the 55 most popular species and get them to try some of the 30,000 to 40,000 underutilized varieties — an effort that might mean changing the names of such potential delicacies as the cancer crab and the rat-tailed flounder.
Some fisheries experts are putting great faith in aquaculture, or sea farming. In Washington, Biologist Jon Lindbergh, son of the aviator, is pioneering in the farming of salmon. After the fish come home to spawn, their eggs are collected and hatched in incubators. The fry are then raised until they are large enough to be kept in offshore pens for harvesting. On St. Croix, in the U.S. Virgin Islands, Lamont-Doherty scientists have successfully grown oysters, clams and scallops in artificial ponds, using nutrient-rich water piped in from the depths of the Caribbean.
Woods Hole Marine Biologist John Ryther has devised an even more ingenious aqua-farming scheme using partially treated sewage water from the Cape Cod town of Wareham. In his ponds, Ryther raises a thick harvest of plankton, which is then fed to baby oysters. To remove whatever ammonia, phosphates or nitrates the oysters and plankton may have left behind, he runs the sewage water over beds of seaweed, which also thrives on these chemicals.
In the future, Ryther also plans to raise abalone as well as brine shrimp, which could be used to nourish rainbow trout.
The remarkable thing about Ryther's ponds is that in addition to purifying the sewage, almost everything produced in them is potentially marketable — even the seaweed, which contains a widely used chemical stabilizer.