Parts of the Great Barrier Reef have suffered the steepest annual decline in live coral cover following the worst bleaching events in nearly four decades. The Australian Institute of Marine Science, or Aims, said that two of the three areas monitored by researchers since 1986 have suffered coral losses this year.

Australia's Great Barrier Reef has suffered the largest decline in coral cover in two of its three regions over the last year, research released on Wednesday showed, following a mass bleaching of its corals that was among the worst on record.

The Great Barrier Reef has experienced its greatest annual loss of live coral across most of its expanse in four decades of record-keeping, Australian authorities say.