The Bluewater Revolution (Wired.Com)

The oceans of the world are being overfished. The solution: roaming robots that bring fish farming to the open seas.

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The buoy is the antenna, eyes, and brain of a sprawling apparatus suspended beneath the surface like a huge aquatic insect, its legs of thick steel chain tethered to the ocean floor. The creature's body is a group of three cages, each resembling a gigantic toy top. Inside the cages are swirling, stupid mobs of fish. The apparatus, an experiment operated by the University of New Hampshire, makes up the first fish farm ever on the open ocean. But this undertaking is more than the latest step in humankind's long effort to tame the seas. The university's Open Ocean Aquaculture Project may represent the best hope for saving those seas - or at least much of the life within them.

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Today the abundance Huxley extolled is on the verge of disappearing. Unless something changes soon, biologist Daniel Pauly recently warned in The New York Times, there will be nothing left for the next generation but "plankton stew."
inhabitants.

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Ping-ponging slowly between continents, these enormous, largely automated underwater ranches would drift into big-city harbors - fresh fish by the ton, delivered daily. No more giant factory ships with illegal 20-mile-long drift nets! No more airfreighting frozen slabs of tuna from the Atlantic for auction in Tokyo! Instead, hatcheries in Mexico would send baby tuna to Japan in million-cubic-foot cages. By the time the floating farms reached Tokyo, the fish, cosseted in their cages like Kobe cattle in their stalls, would be ready for sashimi.

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http://www.wired.com/wired/archive/12.05/fish.html