Florida scientists hunt for heat-resistant coral

University of Miami scientists and trained volunteer divers are planting young coral off Florida and studying which species may better withstand warming oceans.

The work is part of the university's long-running Rescue a Reef programme. During a recent dive to Rainbow Reef, about three miles offshore from Key Biscayne, participants planted coral and checked how others were faring in warmer waters.

Programme manager Devon Ledbetter said some species may be more resilient and better able to survive and recover from heat stress. She said researchers had anecdotally seen Mountainous Star Coral appear most resilient to bleaching and thermal stress.

The programme has planted 615 coral so far this summer, including 228 that are part of a thermal bleaching study. Researchers use colour reference charts to record pigmentation and detect early signs of heat stress, then share results with state environmental and wildlife authorities.

A record-breaking marine heat wave that began in 2023 left elkhorn and staghorn, two important coral species, “functionally extinct” in Florida's Coral Reef. The National Oceanic and Atmospheric Administration believes the fourth global coral bleaching event likely ended in mid-2025, but a very strong El Niño could bring more widespread bleaching, including in Florida's waters.

Coral reefs support marine ecosystems and help protect coastlines from storm-driven erosion and flooding. The Rescue a Reef programme began in 2015.