Coral decline in Great Barrier Reef 'unprecedented'

Reef monitoring program shows northern section has lost half of its coral coverA steep decline in coral cover right across the Great Barrier Reef is a phenomenon that “has not been observed in the historical record”, a new report by the Australian Institute of Marine Science says.The institute, Australia’s government-backed marine research agency, periodically releases results of a long-term reef monitoring program. Each reef along the Queensland coast is visited by researchers