Corals may be tougher than we thought, but the heat’s still on
Corals may be able to roll with the punches of climate change better than initially thought in coming decades, but need rising temperatures to slow to have a fighting chance.
Latest research suggest corals are more resistant than previously thought. (File image)
That’s the finding of new Queensland-led research, published on Monday and based on an analysis of 95 trait measurements across 19 species of reef-building corals from previous studies.
The authors determined corals, which have suffered widespread bleaching events in Australia this century, can pass down abilities to survive under environmental stresses such as rising temperatures through their genes.
“We found their ability to pass on adaptive traits is maintained despite increasing temperatures,” said lead author Kevin Bairos-Novak, a PhD candidate at James Cook University’s Coral Centre of Excellence.
“In particular, corals that are better than average at survival, growth and resisting bleaching stress under future ocean conditions should be good at passing those advantages on to their offspring.”
But the corals won’t be able to make the most of these innate abilities unless current rates of global warming are cut.
Associate Professor Mia Hoogenboom, also from the Coral CoE at JCU, said current rates of climate change are moving “too fast for coral adaptation to keep up”.
Her fellow co-author Sean Connolly explained evolution needs time to generate new variation in coral traits, including temperature tolerance.
“If we can curb climate change, and stabilise temperatures, many coral species will have a shot at adapting to warmer temperatures,” said Professor Connolly of the Panama-based Smithsonian Tropical Research Institute.
The fossil record shows rapid environmental change can lead to very high rates of extinction, Bairos-Novak said.
“However, our findings show that corals are fighters,” he added.
“They are good at passing beneficial traits onto the next generation and the next – helping them cope with the stresses they face. This is what may help them navigate the next few decades better than we previously thought.”
It comes after the Great Barrier Reef – the world’s largest coral reef system – was left off a World Heritage site “in danger” list in July after a UNESCO committee agreed to delay any decision.
Federal politicians lobbied against the proposal, fearing it would hurt the image of the natural wonder and tourism jewel.
Instead, UNESCO gave Australia until February 2022 to upgrade its protection of the reef before making a ruling next year.
