Lifeboat Foundation

The area surveyed represents two-thirds of the Great Barrier Reef.

Almost half of the reefs studied had between 10% and 30% hard coral cover, while about a third of the reefs had hard coral cover levels between 30% and 50%, the report said.

While higher water temperatures led to a coral bleaching event in some areas in March, the temperatures did not climb high enough to kill the coral, the agency said.