Reef in crisis: scientists despair as corals perish

Coral bleaching around Great Barrier Reef islands has left researchers feeling "ecological grief". (HANDOUT/UNIVERSITY OF SYDNEY)

All along the Great Barrier Reef countless corals lie dead and dying in pretty turquoise waters, leaving the scientists who study them heavy with despair.

Some have been reduced to tears after visiting familiar research sites and finding landmark corals lifeless and smothered in brown algae.