Buildings, pavement, golf courses, and other development are taking big bites out of America's coastal wetlands and forests, and now new federal data is charting just how much is being lost.
Between 1996 and 2011, total coastal forest cover dropped by more than 16,000 square miles—an area roughly the size of Delaware, Maryland, and Rhode Island combined. Some 1,536 miles of wetlands were lost over that period as well, according to the data from the National Oceanic and Atmospheric Administration.
Here's what that looks like in the Southeast, where 510 square miles of wetlands—a swath more than 7 times the size of the District of Columbia—vanished between 1996 and 2011.
Development gobbled up more than half of that area.
And development is a key driver of coastal wetlands loss nationwide, accounting for about 40 percent, according to Nate Herold, a NOAA scientist who heads the mapping program at NOAA's Coastal Services Center in Charleston, S.C. It's a lesser cause of coastal forest loss, accounting for about 8 percent, he said.
NOAA, in a summary of the data, noted some good news in Florida, where some areas have seen "modest" wetlands gains due to restoration efforts in the Everglades and other factors. There has also been some wetlands restoration in other regions as well, Herold said.
Reforestation efforts have slowed the decline of coastal forests. More than 27,500 square-miles were lost in coastal regions, but replanting efforts kept the net loss to 16,483 square-miles.
Overall, however, the trend is toward disappearance. Over the 15 years surveyed, the Gulf Coast lost 996 miles of wetlands, "due to land subsidence and erosion, storms, man-made changes, sea level rise, and other factors," NOAA said.
Their report notes that while the Great Lakes saw some wetland gains, that was largely because drought and lower lake levels created new marshes and beaches.
NOAA said that changes to the coastal landscape can increase risks from climate change as barriers to rising sea levels and storm surges disappear.
The agency hopes that it's data and mapping services, part of its Land Cover Atlas program, can help regions prepare.
"The ability to mitigate the growing evidence of climate change along our coasts with rising sea levels already impacting coastlines in ways not imaged just a few years ago makes the data available through the Land Cover Atlas program critically important to coastal resilience planning," said Margaret Davidson, a top official with NOAA's ocean and coastal resource programs.