A covenant of salt

HALFWAY down Mexico’s Baja California peninsula is a dazzling sight; the world’s largest sea-salt plant, owned jointly by the Mexican government and Mitsubishi Corporation, Japan’s largest trading house. Salt flats covering an area a third the size of Tokyo stretch as far as the eye can see, producing about half of Japan’s salt imports. Its advocates say the raw material has a rare quality. The white crystals, dried by the sun, are drawn from seawater in an inlet of the Pacific coast so pristine that grey whales travel from the Arctic to breed there. Yet for all its allure, the place is immersed in a bitter dispute over how to value the world’s only edible rock.