Coral able to protect skeleton against ocean acidification

Image at the top:  Great Barrier Reef, Australia. An intertidal 'micro-atoll'. Photo: Isobel Bennett.

Coral colonies of P. cylindrica have a unique internal solution to the problem of forming their skeletons and building reef structures in the face of rising ocean acidification.

"Our research shows that some corals living in dynamic reef systems (P. cylindrica) have the ability to maintain a nearly constant pH within their calcifying fluid, regardless of the pH of the surrounding environment," says Lucy Georgiou from the ARC Centre of Excellence for Coral Reef Studies.

"This enables them to continue to form their calcium carbonate skeleton even under relatively low pH conditions."

Is adaption only local?

The regulatory mechanism allows the coral to grow at a relatively constant rate, suggesting they may be more resilient in this environment to the effects of ocean acidification than previously thought. While the findings are positive, it's not yet known if the adaption is species-specific and limited to colonies in dynamic reef systems.

"This is most likely only typical to corals from reefs such as Heron Island lagoon where temperature and pH fluctuations vary greatly on a daily to seasonal basis," says Ms Georgiou.