Coral reefs will continue to experience severe heat stress as rising temperatures cause the oceans to become unbearably hot – but a new study shows that altering their feeding habits could allow local populations to avoid total extinction.
Research into two species of coral native to Hawaii revealed that warmer waters caused by climate change play an important role in coral bleaching — a process that causes coral to lose their color — significantly disrupting coral health and growth. The effect that ocean acidification, a process that causes seawater to become more acidic due to the excess amount of carbon dioxide it has absorbed, has on heat-stressed coral was also investigated.
Over the last decade, there has been a rise in the incidence and severity of , senior author of the study and a professor in earth sciences at Ohio State. “It gives us more leverage in following up on evaluating how we can protect corals and manage bleaching events by manipulating the environment to their favor.”
While predictions about coral survivorship in the face of human-induced climate change do make room for hope concerning the fate of corals, these assumptions are based on the adherence to current climate mitigation goals, said Grottoli.
For example, it is possible that corals could adapt enough to survive a 2 degree Celsius increase in global temperatures. However, Earth’s current unmitigated acceleration to 4 degrees of warming by the end of the century could eradicate coral completely, she said.
As the next few decades are critical to determining the reality of these scenarios, Dobson’s future work will continue to investigate the impact of thermal stress on the ecology of coral reefs in other regions.
“When you do experiments with living animals in a natural setting, there’s always some degree of unpredictability, as we saw with the unexpected second heat-stress event we studied,” said Grottoli. “Ultimately, you have to roll with it because the work matters, and sometimes the things you didn’t plan to learn are the parts that are the most interesting.”
This research was supported by the National Science Foundation. Other co-authors include Jeremy C. Williams and Rowan H. McLachlan from Ohio State and Christopher P. Jury and Robert J. Toonen from the University of Hawai‘i.
