Florida researchers bring endangered elkhorn coral pieces ashore to protect them

KEY BISCAYNE, Fla. — Scientists working to save a coral species from extinction transported 30 pieces from nurseries off the Florida coast to a hatchery on land in recent days, fearing that warming waters could trigger a mass bleaching event this summer that could wipe them out.

Elkhorn coral populations were decimated by a 2023 heat wave and a less severe one in 2024 that left them functionally extinct — meaning remaining colonies are too small and far apart to reproduce in the wild — from Broward County to the Florida Keys, said Diego Lirman, associate professor of marine biology at the University of Miami. Heat causes coral to bleach, which can be fatal if it lasts long enough.

Researchers have been propagating the elkhorn at coastal nurseries, but decided to bring some ashore now because of indications that 2026 will be “a really bad year” for bleaching — perhaps even worse than 2023, Lirman said. Coral has been showing indications of heat stress as water temperatures rise.

Coral populations are living creatures that form reefs, globally important for seafood production, protecting coastlines from storm surges and tourism. But scientists fear they could be lost because of climate change: Florida coral has experienced four mass bleaching events in the past decade.

“They seem to be blending into each other and corals are not getting time to recover,” Lirman said.

Divers focused on collecting genetically diverse coral pieces, wrapping each in wet bubble wrap and placing them in coolers before sanitizing them and putting them in tanks at the hatchery.

The university exchanges coral with other researchers and facilities to preserve as much original genetic diversity as possible in nurseries and in hatcheries, “so if one goes down you don’t lose the last remaining genetic information,” Lirman said.

“You never know: You may have some that are resistant to disease, some that are resistant to temperature, some that are resistant to acidification,” he said. “Once we lose them, then that information is lost.”

Lavandier and Webber write for the Associated Press.