Please select your home edition
Barton Marine 2019 728x90

DNA reveals the past and future of coral reefs

by ARC Centre of Excellence for Coral Reef Studies 22 Oct 2022 04:54 UTC
Protective mucous dripping of a coral colony exposed at low tide Beagle Reef © Zoe Richards

New DNA techniques are being used to understand how coral reacted to the end of the last ice age in order to better predict how they will cope with current changes to the climate.

James Cook University's Dr Ira Cooke was senior author of the study. He said when corals become stressed they often bleach and die, but not all corals experience stress equally.

"This is often due to genetic differences between species, but it's usually very difficult to determine which genes are responsible. In situations where the differences evolved relatively recently - thousands not millions of years ago - it's much easier to do so," said Dr Cooke.

He said the end of the last ice age is relatively recent in evolutionary terms and it sometimes forced corals to adapt to stresses similar to those projected under future climate change.

"Until now it hasn't been possible to look at this period in coral evolution because most of the techniques available have provided information about much older events. But by sequencing the whole genomes of many individuals within a single species we have now been able to access this crucial period of coral evolutionary history," said Dr Cooke.

JCU PhD candidate Jia Zhang, lead author of the study, said sea-level change has reshaped the Kimberley coral communities many times in the past.

"This study examines how these historical changes have influenced coral population sizes, how far they disperse, and their ability to adapt," said Ms Zhang.

She said the researchers compared the genomes of corals from the inshore Kimberley with those inhabiting more benign offshore locations (Ashmore Reef and Rowley Shoals).

"We found there were clear genetic distinctions, akin to races, between corals from the three locations we studied but most obviously between the inshore and offshore reefs, and that these genetic groups had arisen around the time the last ice-age ended.

"This was when sea levels rose dramatically allowing corals to colonise the Kimberley region, and to re-establish themselves on the tops of offshore atolls," said Ms Zhang.

Co-author of the study, Dr Zoe Richards from Curtin University's School of Molecular and Life Sciences said as the sea-level rose between 20 and 10 thousand years ago, corals dispersed to new habitats.

"But only those individuals with the right genetic makeup were able to survive. This selective process is visible in the genomes and tells us which genes were important for survival," said Dr Richards.

She said corals from the Kimberley had tell-tale patterns in their genomes revealing genes that were modified through natural selection around the time of the last ice-age when they colonised this tough inshore habitat.

Dr Cooke said one specific type of genes called peroxinectins have been under especially strong and recent evolutionary pressure (natural selection) in inshore Kimberley corals.

"These genes clearly evolved different versions in inshore corals and it's likely that this helps them cope with the extreme environmental conditions there. These genes provide a roadmap to help further understand how corals can survive turbid, hot and exposed conditions like those in the Kimberley"

This study was funded by ARC Linkage Project LP160101508.


Zhang J, Richards Z, Adam A, Cheong XC, Shinzato C, Gilmour J, Thomas L, Strugnell J, Miller D, Cooke I. 2022. 'Evolutionary responses of a reef-building coral to climate change at the end of the last glacial maximum'. Molecular Biology and Evolution. DOI:

Related Articles

The double burden of climate change
A new study on the effects of climate change in five tropical countries A new study on the effects of climate change in five tropical countries has found fisheries are in more trouble than agriculture, and poor people are in the most danger. Posted on 9 Jul 2022
Fade to grey
Fish communities become duller as coral reefs die James Cook University researchers have found brightly coloured fish are becoming increasingly rare as coral declines, with the phenomenon likely to get worse in the future. Posted on 26 Mar 2022
Concerns as development threatens reefs
A stark warning about the impacts of urban growth on the world's coral reefs A new study has delivered a stark warning about the impacts of urban growth on the world's coral reefs. Posted on 10 Mar 2022
New data shows coral everywhere face catastrophe
The refuges will provide almost no escape Alarming new research shows global warming of 1.5 degreesC relative to pre-industrial levels will be catastrophic for almost all coral reefs - including those once thought of as refuges. Posted on 4 Feb 2022
Coral identity crisis
A new way to distinguish and identify coral species Researchers have found a new way to distinguish and identify coral species—providing crucial information to help manage coral reefs in a warming world. Posted on 30 Nov 2021
Corals roll with the punches
Corals may be able to cope with climate change in the coming decades A new study suggests corals may be able to cope with climate change in the coming decades better than previously thought- but will still struggle with ever-faster rates of climate change. Posted on 8 Sep 2021
Measuring conservation in a way that counts
The term 'save' in conservation needs to be better defined A new study raises questions on whether current conservation science and policy for protected areas could be saving more biodiversity—with political and economic expediency often having taken precedence in the past. Posted on 30 Jul 2021
More 'fairness' needed in conservation
A new approach is needed if protected areas are to be effective New research shows what is often assumed to be 'fair' in conservation practice may not be considered so by the very people most affected by it—and a new approach is needed if protected areas are to be effective. Posted on 12 Jun 2021
Time running out to save coral reefs
A window of opportunity to save the world's coral reefs - but time is running out New research on the growth rates of coral reefs shows there is still a window of opportunity to save the world's coral reefs - but time is running out. Posted on 13 May 2021
Half a trillion corals
World-first coral count prompts rethink of extinction risks For the first time, scientists have assessed how many corals there are in the Pacific Ocean—and evaluated their risk of extinction. Posted on 3 Mar 2021
Cure Marine - Cure 55 - FOOTERCrewsaver 2021 Safetyline FOOTERCyclops Marine 2023 November - FOOTER