Florida's Mangroves Face Death by Rising Sea Level - Atlas Obscura

Florida’s Mangroves Face Death by Rising Sea Level

The Everglades and coastal communities are in peril.

Mangrove trees at dawn.
Mangrove trees at dawn. Keith Kapple / Alamy

This story was originally published by The Guardian and appears here as part of the Climate Desk collaboration.

Florida’s mangroves have been forced into a hasty retreat by sea level rise and now face being drowned, imperiling coastal communities and the prized Everglades wetlands, researchers have found.

Mangroves in south-east Florida in an area studied by the researchers have been on a “death march” inland as they edge away from the swelling ocean, but have now hit a manmade levee and are likely to be submerged by water within 30 years, according to the Florida International University analysis.

“There’s nowhere left for them to go,” said Dr. Randall Parkinson, a coastal geologist at FIU. “They are done. The sea will continue to rise and the question now is whether they will be replaced by open water. I think they will.

“The outlook is pretty grim. What’s mind boggling is that we are facing the inundation of south Florida this century.”

The Everglade National Park in Florida.
The Everglade National Park in Florida. Kunal Mukherjee/CC BY-SA 2.0

Mangroves are made up of coastal vegetation that grows in salty or brackish water. They are considered crucial buffers to storms and salt water intrusion, as well as key habitats for certain marine creatures.

Using aerial photographs, satellite imagery, and sediment cores, FIU researchers found that mangroves just south of Miami were migrating westwards over marshland at a rate of about 100 feet a year until they were halted by the L-31E levee, a flood barrier in Miami-Dade county, where they are now making their last stand.

Previous research has suggested the same phenomenon has happened in other parts of south Florida, making the region more vulnerable to storms, such as Hurricane Irma, which swept up Florida last year, and land loss as the sea rises further.

This Landsat 5 image of Southern Florida shows the transition from the sawgrass prairies to the mangrove forests.
This Landsat 5 image of Southern Florida shows the transition from the sawgrass prairies to the mangrove forests. USGS Landsat/CC BY 2.0