Coral bleaching on Eyrie Reef, March 2024. Photo: George Roff//CSIRO
Nature has a remarkable ability to adapt to changing conditions. However, due to global warming, the pace of change may have advanced past the capabilities of natural selection. That’s why a group of scientists have come together to help the process along by selectively breeding corals to survive ocean heatwaves.
Human-caused global warming has led to increasingly frequent and severe marine heatwaves. The result has been mass coral bleaching and mortality, leading to a global decline in coral reefs. Just this year, the NOAA announced we are in the midst of yet another global coral bleaching event, the fourth on record and the second in the past decade.
In order to combat that process, a team of experts from Newcastle University’s Coralassist Lab has conducted a study on selectively breeding corals in order to enhance their heat tolerance. The study, published in the journal Nature Communications, found the approach successful. They were able to increase the heat tolerance of adult coral offspring within just one generation.
However, there were shortcomings to the proposed solution. While the scientists were able to selectively breed for short-stress tolerance, i.e. surviving heatwaves, this did not improve the corals’ ability to survive long-term exposure to extreme heat. They concluded that, while selective breeding could be a viable tool to improve corals’ survivability, we still need to work against climate change to ensure their long-term future.
“This work shows that selective breeding is feasible but not a silver bullet solution and that more research is needed to maximize breeding outcomes,” study lead author, Liam Lachs, a Postdoctoral Research Associate at Newcastle University, wrote in a press release. He added that, “In parallel, rapid reductions of global greenhouse gas emissions are an absolute requirement to mitigate warming and give corals an opportunity to adapt.”
