Good bacteria vital to coral reef survival

Starfish surrounded by decomposing coral on the Great Barrier Reef. Image courtesy of XL Catlin Seaview Survey.

Scientists say good bacteria could be the key to keeping coral healthy, able to withstand the impacts of global warming and to secure the long-term survival of reefs worldwide.

“Healthy corals interact with complex communities of beneficial microbes or ‘good bacteria’,” says Tracy Ainsworth from the ARC Centre of Excellence for Coral Reef Studies at James Cook University who led the study. “It is very likely that these microorganisms play a pivotal role in the capacity of coral to recover from bouts of bleaching caused by rising temperatures.”

“Facilitating coral survival and promoting coral recovery are growing areas of research for coral reef scientists,” says co-author Ruth Gates director of the Hawaiʻi Institute of Marine Biology, University of Hawaiʻi at Mānoa. “To do this we need to explore and understand the bacteria that help keep corals and coral reefs healthy.”

Good bacteria promote resilient coral

Ainsworth and Gates have identified new directions for research in understanding coral survival in rapidly changing reef environments.

“We know that lasting changes to the community of beneficial bacteria affects important aspects of the function of host organisms such as humans or corals, including their ability to withstand further stress,” says Ainsworth.

“Corals rely on good bacteria but crucially we don’t yet understand these microbes well enough to know how they influence coral survival.”

Their latest research has been published in the journal Science, and gives an overview of the current understanding of bacterial communities on corals. It highlights the vital importance of good bacteria to coral health.

The scientists discuss how corals, and coral reefs that survive large-scale changes in the environment over the coming decades, are likely to be very different from those of today.

They say the interaction between corals and good bacteria is crucial to long-term survival.

Their work comes from recent advances in understanding the complexity of the coral’s genetic make-up and the unique bacterial communities that corals maintain.