"Under international law, countries control the waters within 200 of their shores. Beyond that, the oceans and a hundred million square miles of seafloor, is referred to in I.S.A.-speak simply as the Area, and are considered “the common heritage of mankind.” Scattered across the Area are great riches. Mostly, these take the shape of lumps that resemble blackened potatoes, but consist of layers of ore that have built up around bits of marine debris, such as ancient shark teeth. A single nugget might take some 3 million years to form. Collectively, the nodules on the bottom of the ocean contain six times as much cobalt, three times as much nickel, and four times as much of the rare-earth metal yttrium as there is on land. They contain six thousand times as much tellurium, a metal that’s even rarer than the rare earths."But seabed mining poses environmental hazards of its own.