Sydney: Unfazed by the most severe ecological threats, some coral reefs may yet be adapting to warmer oceans.
Coral populations which unexpectedly survived a massive bleaching event in 2010 in southeast Asian waters had also experienced severe bleaching during an event in 1998, researchers report.
Analysing three sites during the 2010 event, the team led by University of New South Wales (UNSW) found that in Indonesia, corals responded to higher temperatures in a typical way, with fast-growing branching species -such as staghorn corals, suffering severe die-offs.
But at sites monitored in Singapore and Malaysia, the usual trend was reversed: normally susceptible colonies of fast-growing Acropora corals appeared healthy and fully pigmented, while most colonies of massive coral were severely bleached, the journal Public Library of Science ONE reports.
"Mass coral-bleaching events, caused by a breakdown in the relationship between the coral animals and their symbiotic algae, are strongly correlated with unusually high sea temperatures and have led to widespread reef degradation in recent decades," noted James Guest, who led the study.
Guest is currently a joint research fellow at the UNSW Centre for Marine Bio-innovation and the Advanced Environmental Biotechnology Centre at Singapore`s Nanyang Technological University, according to an UNSW statement.
"The severity of these events varies considerably but until now we`ve seen one consistent trend: certain types of coral tend to be more resistant to bleaching than others," said Guest.
"This has led to the prediction that hardier, slow-growing massive species will replace less hardy, fast-growing branching species on reefs in the future."