National Geographic : 1977 May
of Engineers' controversial decision to halt further development and thereby save two big mangrove tracts on Marco is a milestone for all this country's wetlands. The corps essentially ruled that wetlands are too valu able a public resource to be squandered for developments that are not clearly in the pub lic interest. (The value of Florida's mangrove wetlands for fishing, tourism, and recreation has been estimated at about $4,000 per acre per year.) Owners of wetlands, it would now appear, can no longer do whatever they want with their property. Mangrove Nurseries Yield Shrimp Few people are as pleased by the corps' decision as biologist Bernie Yokel, director of the Rookery Bay Marine Research Station, tucked into the 5,500-acre Rookery Bay Sanc tuary, a splendid preserve of mangrove coast and islands just a short boat ride north of Marco Island. Bernie, a jovial, outspoken de fender of mangrove purity, has no use for new neighbors. He understands too well the importance of the mangroves. "Almost all the game fish and commercial species in the Florida mangroves go back to the open sea to spawn," he explained. The most commercially important of these are the pink shrimp, which, as adults, support at least an 18-million-dollar-a -year industry. Hatched in the Dry Tortugas, nearly a hun dred miles away, these shrimp mature in the mangrove estuaries of Florida Bay and Ever glades National Park. The juveniles migrate back to the Tortugas, where shrimpers scoop up some 16 million pounds each year as the adults spawn. Nearly 75 percent of this coun try's pink shrimp grow up in these mangrove nurseries. "One female pink shrimp may produce 500,000 or more eggs," said Bernie. "Spawn ing occurs all year, but the bulk of the larvae are produced in late spring and early sum mer as specks you can hardly see. Those specks make this incredible migration back Perfect cover for tricky raccoons, the gnarled roots of a coastal mangrove swamp foil the most dauntless of coonhounds. At low tide, thousands of coon oysters-one of the predator's favorite foods-can be found clinging to mangrove prop roots.