After an exceptionally warm summer, Florida's coral reefs are beginning to feel the heat.
Mass coral bleaching has occurred along the state's coastline since mid-July, leaving experts worried for the long-term survival of these already-fragile reefs.
"Sustained periods of bleaching can cause long-term damage to corals and can lead to coral mortality," a spokesperson for Dry Tortugas National Park, almost 70 miles west of Key West, said in a post on Facebook.
"Unfortunately, current water temperature forecasts suggests that the Florida Keys, including Dry Tortugas, may be susceptible to high water temperatures through early October, causing concern that bleaching will continue to persist too." Dry Tortugas National Park is 99 percent underwater with seven small islands and is home to the third-largest barrier reef in the world.
Corals get their food from symbiotic algae that live inside them. These are also responsible for the corals' color. However, when water temperatures increase, the algae start producing molecules that can damage their coral host. The coral then kick out their resident algae, resulting in them losing their color and food source. If high temperatures persist, the corals will eventually starve.
In the same Facebook post, the spokesperson for the 100-square-mile Dry Tortugas National Park shared photos from July 2022 and August 2023, highlighting the devastation caused by this year's hot weather.
The first photo shows a diver collecting samples from a healthy ochre-colored elkhorn coral colony. The second image was taken on August 4, 2023, and presents a stark contrast, as the once-colorful corals are white and barren.
"About one year later, the same elkhorn coral colony has sustained physical damage from Hurricane Ian and is bleaching due to unusually warm water temperatures," the national park spokesperson said.
"Coral reefs are incredibly important to us," the national park said. "Sadly, the unusually warm water temperatures affecting most of Florida's Coral Reef are also affecting Dry Tortugas National Park and have led to coral bleaching."
This chart, provided by Statista, shows the conservation status of the world's reef-building corals in 2022.
Since the 1870s, we have already lost half of the living coral in our oceans, according to the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services. Severe bleaching events used to happen only ever 25 years, but now they happen every six.
Coral reefs are some of the most biodiverse places on Earth and directly support around 500 million people globally. The corals themselves give the reefs their structure, just like the trees in the rainforest, and without them this whole ecosystem would collapse.
With record high sea-surface temperatures in Florida Keys, the National Oceanic and Atmospheric Administration is working hard to rescue live fragments from each genetically unique coral remaining in Florida's reefs so that their genetic diversity can be replanted and restored in the future.
Uncommon Knowledge
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Newsweek is committed to challenging conventional wisdom and finding connections in the search for common ground.
About the writer
Pandora Dewan is a Senior Science Reporter at Newsweek based in London, UK. Her focus is reporting on science, health ... Read more
