Some corals have DNA to adapt to warmer climate

Some coral species are better at adapting to climate change than others, and they may be able to pass their hardy DNA onto the next generation, said a study Thursday.

Coral reefs are declining fast in many parts of the world due to pollution, warming seas, disease and storms. But the findings in the journal Science suggest these ocean floor animals may be more resilient than previously believed, and that targeted conservation efforts could help them bounce back.

Researchers in Australia cross-bred samples of a type of branching coral known as Acropora millepora from two different locations about 500 kilometers (300 miles) apart.

Some came from Princess Charlotte Bay, a warmer area of the Great Barrier Reef that is closer to the equator.

Others came from Orpheus Island, about five degrees of latitude to the south where the waters are about two degrees Celsius (four Fahrenheit) cooler.

When researchers crossed the two, they found that those with parents that came from warmer waters were 10 times more likely to survive under heat stress than those that were native to cooler waters, suggesting that the animals' had some natural resilience in their genetic makeup.

"Our research found that corals do not have to wait for new mutations to appear," said co-author Mikhail Matz, an associate professor of integrative biology at The University of Texas at Austin.

"Averting coral extinction may start with something as simple as an exchange of coral immigrants to spread already existing genetic variants."

Conservationists worldwide are already at work growing corals in underwater nurseries and transplanting corals in different places.

But some have raised concern that too much human interference in planting new reefs and moving corals around could introduce disease or otherwise harm the natural environment on the ocean floor.

"What this paper shows is there might be an actual value to doing that and we should start doing pilot studies to investigate," said Andrew Baker, associate professor of marine biology and ecology at the University of Miami Rosentiel School of Marine and Atmospheric Science.

Baker, who was not involved in the study, called the work "very promising" said it showcases a new approach to coral restoration that should be a boon to conservationists' efforts.

"What is exciting about this study is it is the first time people have actually cross bred corals from different thermal regimes -- in this case different latitudes -- and then looked at the heritability of thermal tolerance which is obviously a big question in terms of figuring out whether and how corals are going to adapt to climate change in the coming century or so," he told AFP.

"It allows us to not just sort if sit back and wait to see what happens," he added.

"If you know or have an idea of how the oceans are going to warm in a certain area you might consider taking a locally warm-adapted corals from area into another area that is slightly cooler but that is expected to warm."
Source: AFP