Florida's coral reef bleaching months ahead of schedule under extreme heat

Michelle Butterfield GlobalNews.ca
WATCH: Florida's coral reefs are not faring so well under the extreme heat gripping the globe, to the point where they are prematurely turning white as water temperatures soar, experts say. Jackson Proskow reports.

Florida’s coral reefs are not faring so well under the extreme heat gripping the globe, to the point where they are prematurely turning white as water temperatures soar, experts say.

Some reefs in the Florida Keys have begun to lose their colour weeks earlier than normal and record-high water temperatures are to blame, Katey Lesneski, research and monitoring co-ordinator for Mission: Iconic Reefs, told The Associated Press.

“The corals are pale, it looks like the colour’s draining out,” said Lesneski, who has spent several days on the reefs over the last two weeks. “And some individuals are stark white. And we still have more to come.”

The Coral Restoration Foundation said in one coral reef restoration site off the state’s coast, the extreme temperatures have proved deadly.

“On July 20th, CRF teams visited Sombrero Reef, a restoration site we’ve been working at for over a decade. What we found was unimaginable — 100 per cent coral mortality,” Phanor Montoya-Mayoa, a restoration program manager at the foundation, told CBS News. “We have also lost almost all the corals in the Looe Key Nursery in the Lower Keys.”

This extreme heat can be deadly for the reefs, which are considered important ocean animals. When the temperature of the ocean becomes too warm, the algae normally present in the coral’s tissues depart, causing the coral to turn white — a.k.a. coral bleaching.

Not all bleaching events are fatal for reefs, but it does cause much more stress for the coral and makes them more vulnerable to future bleaching events.

Scientists with the National Oceanic and Atmospheric Administration (NOAA) this week raised their coral bleaching warning system to Alert Level 2 for the Keys, their highest heat stress level out of five. That level is reached when the average water surface temperature is about 1 C above the normal maximum for eight straight weeks.

Surface temperatures around the Keys have been averaging about 33 C, well above the normal mid-July average of 29.5 C, said Jacqueline De La Cour, operations manager for NOAA’s Coral Reef Watch program. Previous Alert Level 2s were reached in August, she said.

CNN meteorologist Derek Van Dam points out that ocean temperatures along Florida’s coast this week have topped 38 C in some places, making them as warm as some hot tub waters.

“We are at least a month ahead of time, if not two months,” Andrew Bruckner, research co-ordinator at the Florida Keys National Marine Sanctuary, told AP.

“We’re not yet at the point where we are seeing any mortality … from bleaching. It is still a minor number that are completely white, certain species, but it is much sooner than we expected,” Bruckner said, adding that the Florida Keys have lost between 80 and 90 per cent of their reef systems in the last 50 years.

Bruckner said it’s hard to predict what’s in store for the reefs as the summer continues — a hurricane or tropical storm could churn up the water and cool it down or dusty air from the Sahara Desert moving across the Atlantic and settling over Florida could dampen the sun’s rays, lowering temperatures.

According to the state, Florida’s coral reef extends almost 600 kilometres and protects the land from catastrophic storms. It also plays an important role in the area’s tourism and food sectors, with more than 71,000 jobs being supported thanks to the existence of the reef.

R. Scott Winters, CEO of the Coral Restoration Foundation, told CBS that climate change is having an “undeniable” impact on the world’s reefs.

“This crisis must serve as a wake-up call, emphasizing the need for globally concerted efforts to combat climate change,” Winters said.

“This is not a partisan issue; everyone will be affected. The climate crisis impacts our way of life and all life on Earth.”

© 2023 Global News, a division of Corus Entertainment Inc.

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