Australia’s two world heritage-listed reefs – Ningaloo on the west coast and the Great Barrier Reef on the east – have been hit simultaneously by coral bleaching that reef experts have called “heartbreaking” and “a profoundly distressing moment”.

Teams of scientists on both coasts have been monitoring and tracking the heat stress and bleaching extending across thousands of kilometres of marine habitat, which is likely to have been driven by global heating.

Paul Gamblin, the chief executive of the Australian Marine Conservation Society, said history would “record this profoundly distressing moment” when two world famous reefs both suffered widespread damage at the same time.