Great Barrier Reef watchers anxiously await evidence of coral bleaching from aerial surveys

Planes will this week cover areas in the southern half of the reef that escaped earlier bleaching but may have undergone high levels of heat stress

The full impact of coral bleaching across the Great Barrier Reef will become clearer this week as aerial surveys of hundreds of reefs are completed in the bottom two thirds of the world's biggest reef system.

An aerial survey carried out last week over almost 500 individual reefs between the Torres Strait and Cairns revealed some severe bleaching of corals closer to shore, but almost none on outer reefs.