Proximity to land determines coral reef's response to climate change

Coral reef communities are affected differently by climate change events and depends upon proximity to the mainland, finds a study.

Researchers from the University of Exeter showed severe weather and environmental disturbances, like cyclones or thermal coral bleaching, affect specific areas of coral reefs differently.

"It is common to find distinct communities of coral and reef fish living together on coral reefs at different locations across the continental shelf," said lead author Eva McClure from James Cook University, in Townsville, Australia.

"But until now, we haven't known whether these different communities respond in the same way to environmental disturbances or whether specific local conditions might result in different community responses," McClure said.

Coral reefs are made up of thin layers of calcium carbonate (limestone), secreted over thousands of years by billions of tiny soft-bodied organisms called coral polyps. Among the world's most diverse marine ecosystems, they are home to thousands of species of plants and animals.

The team studied the effect of the natural disasters on the Great Barrier Reef, home to more than 1,500 species of fish including clownfish, parrotfish and lionfish. The study showed the number of herbivorous fish species decreased following environmental events.

"After widespread loss of corals due to large storms or severe coral bleaching events, herbivorous reef fish are vital for removing seaweed that starts to grow over the dead corals, to let new corals grow and surviving corals recover," said Laura Richardson, a marine biologist at the University of Exeter in the US.

The study of these herbivorous fish response to environmental events indicates where reefs may be more vulnerable and possibly slower to recover, she noted.

The researchers believe the study offers a pivotal insight to allow for better conservation and management of coral reefs, particularly those reefs exposed to land-based sources of pollution and sedimentation.

--IANS

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