Scripps News: Marine scientist John Bruno became interested in coral reefs as a boy snorkeling in the turquoise waters off the Florida Keys above reefs of golden corals the size of football fields. “It just went on for acres and acres,” recalls Bruno, 43, an associate professor at University of North Carolina-Chapel Hill. “They were just full of fish. We’d see hammerhead sharks on the reef and big critters. That is all gone. “The corals are gone and the big fish are gone,” he says. “That’s …