Can Florida’s corals survive climate change?

The fate of one resilient reef may hold the answer

When marine scientist Ian Enochs jumped into the water at Cheeca Rocks, a small reef in the Florida Keys known for vibrantly colorful corals, what he saw shook him to the core.

“Literally everything was white,” said Enochs, a research ecologist with the National Oceanic and Atmospheric Administration in Miami. “It does not look normal at all; it’s just like a different reef.”

It was July, still early in what would become the hottest summer on record in South Florida, and Enochs was witnessing a mass event bleaching — a telltale trouble sign that corals are struggling in abnormally hot ocean waters. Keys reefs have been hit periodically by bleaching over the decades and recovered, the corals weakened but still alive. But prolonged bleaching can prove fatal. To

Enochs, this looked severe and potentially lethal.

“The flesh, the tissue [of the soft corals] were just falling off of them,” Enochs said, “They were literally falling apart before our eyes.”

Now, as ocean temperatures cool, teams of scientists are engaged in an unprecedented effort to assess not only the heat wave damage but the future of South Florida’s long-ailing reef tract.

Cheeca Rocks, Enochs’ prime study spot for more than a decade, had been considered among the Keys’ healthiest reefs. In the months and years ahead, it will serve as a living — or dying — laboratory. The fate of its corals will help tell scientists like Enochs how and if reefs can survive climate change, which is driving sea temperatures to new highs.

It might take a year to see how much recovers and to assess the final toll. But it’s already clear that the record heat worsened what has been a precipitous decline for corals off South Florida.

RECORD SEA TEMPERATURES OFF SOUTH FLORIDA

Summer 2023 set sea temperature marks up and

ALIE SKOWRONSKI askowronski@miamiherald.com Fragments of staghorn coral hang in a tank at Experimental Reef Laboratory, which is jointly run by NOAA and the University of Miami.

Comparing coral life on the ocean floor in the Florida Keys from 1992 to 2023. 1992 shows what scientists considered about 20-30% stony coral cover, and 2023 shows a mostly dead reef with a few bleached corals that are attempting to recover after this year’s bleaching, according to NOAA scientist Ian Enochs.

ALIE SKOWRONSKI askowronski@miamiherald.com Dr. Phanor Montoya-Maya, center, lowers a tray of coral fragments into the hands of divers at the Coral Restoration Foundation’s underwater nursery in October.

ALIE SKOWRONSKI askowronski@miamiherald.com