The Rock Islands harbour two lineages of thermally tolerant corals; one shows no consistent growth trade-off and occurs on several outer reefs.
Palau’s Rock Islands experience consistently higher temperatures and extreme heatwaves, yet their diverse coral communities bleach less than those on Palau’s cooler outer reefs.
Scientists studying reefs in Palau have identified genetic subgroups of a common coral species that exhibit remarkable tolerance to the extreme heat associated with marine heatwaves.
Importantly, the scientists have also found evidence that larvae from these corals are travelling from their birthing grounds deep in Palau’s lagoons to the outer reef, where they survive and grow, and maintain their heat tolerance.
This suggests that the Rock Islands provide naturally tolerant larvae to neighbouring areas. Finding and protecting such sources of thermally-tolerant corals is key to reef survival under 21st-century climate change.
The Palau research is directly related to the Super Reefs initiative WHOI launched with The Nature Conservancy and Stanford University to locate coral communities that can withstand marine heatwaves, and work with local communities and governments to protect them.