Great Barrier Reef coral halved in 27 years

Amy Coopes in AFP: Australia's Great Barrier Reef has lost more than half its coral cover in the past 27 years due to storms, predatory starfish and bleaching linked to climate change, a study found Tuesday. The research by scientists from the Australian Institute of Marine Sciences (AIMS) and the University of Wollongong warned that coral cover on the heritage-listed reef -- the world's largest -- could halve again by 2022 if trends continued.

Intense tropical cyclones -- 34 in total since 1985 -- were responsible for much of the damage, accounting for 48 percent, with outbreaks of the coral-feeding crown-of-thorns starfish linked to 42 percent. Two severe coral bleaching events in 1998 and 2002 due to ocean warming also had "major detrimental impacts" on the central and northern parts of the reef, the study found, putting the impact at 10 percent.

Two-thirds of the loss had occurred since 1998, with the rate of decline increasing substantially and only three of the 214 individual reefs surveyed across the sprawling 345,000 square kilometre site escaping any impact. "This loss of over half of initial cover is of great concern, signifying habitat loss for the tens of thousands of species associated with tropical coral reefs," the study said.

Author Hugh Sweatman said the findings, which were drawn from the world's largest ever reef monitoring project involving 2,258 surveys over 27 years, showed that coral could recover from such trauma....

A giant clam in the Great Barrier Reef, shot by Janderk, public domain