May 2, 2018

Everglades under threat as Florida's mangroves face death by rising sea level

Everglades, Florida
USA
by
Oliver Milman
,
The Guardian
The Everglades wilderness has already been reduced by half by the construction of dams and canals and to accommodate a booming population. Photo: Getty Images
The Everglades wilderness has already been reduced by half by the construction of dams and canals and to accommodate a booming population. Photo: Getty Images

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.

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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 100ft 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.