Silence On The Reefs



Silence on the reefs
23rd July 2018

By Sandra Pearce
Severe bleaching has changed the ecology on the Great Barrier Reef in Australia, say scientists. 
Healthy coral reefs are alive with the pops, snaps and clicks of the invertebrate creatures that inhabit them. And many newly hatched fish species use these sounds to guide them towards new habitats. 
But scientists say that reefs damaged by coral bleaching and cyclones are quieter than healthy reefs and fail to attract as many new juvenile fish, which are crucial for reef recovery.
An international team published its findings in the Proceedings of the National Academy of Sciences. Study co-author Mark Meekan from the Australian Institute of Marine Science (AIMS) said the results are worrying.
“During bleaching, corals lose their zooxanthellae, they starve to death, they die and live coral cover is replaced by algae. Those young fish graze the reef and keep the algae down. Without the fish suppressing the growth of algae, the corals have essentially no space on the reef and can’t get through,” he said.