Key Takeaways
- Elkhorn and staghorn corals in Florida are now declared ‘functionally extinct’.
- A historic 2023 marine heat wave caused near-total mortality (97.8% to 100%) of these species.
- These corals had been the primary reef builders in the region for 10,000 years.
Two foundational coral species that built Florida’s reefs for millennia have been declared functionally extinct following a devastating marine heat wave in 2023. Research published in the journal Science confirms that elkhorn and staghorn corals can no longer perform their critical ecological roles.
“The numbers of individuals of these species that remain are now so low that they cannot perform their ecological functions in any meaningful way,” said Ross Cunning, a coral biologist with Chicago’s Shedd Aquarium. “This is the functional extinction of two incredibly important ecosystem engineers for coral reefs in Florida.”
Unprecedented Coral Loss
The comprehensive study involved 47 researchers who documented catastrophic losses across Florida’s coral ecosystems. Between 97.8% and 100% of elkhorn and staghorn coral colonies have died in the Florida Keys and Dry Tortugas region.
Since the Ice Age, these corals had created elaborate, branching structures that served as homes for parrotfish, eels, and octopuses. “They’ve been the most important reef builders on these reefs for 10,000 years,” Cunning noted.
The research team reached their conclusions after divers surveyed more than 52,000 coral colonies across nearly 400 sites, providing the most comprehensive assessment of the damage caused by extreme ocean temperatures.



