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. But due to increasing coral cover since 2017, the coral deaths — caused mainly …

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. But due to increasing coral cover since 2017, the coral deaths — caused mainly …