About 100 coral reefs within the Great Barrier Reef have been identified as having particular resilience that may help corals recover from bleaching and other threats.

But researchers warn against relying on a "triage approach" to maintain the reef's health.

Back-to-back bleaching on the Great Barrier Reef triggered widespread coral mortality especially in the northern regions. Credit:ARC Centre of Excellence for Coral Reef Studies

The hardy "robust source reefs" – about 112 in number or about 3 per cent of total coverage – were found to be in cooler, outer reefs.

Their location helped shield them from the recent back-to-back annual bleaching that had devastated corals, the Australian and British researchers found.