Changing Chesapeake: Rising Sea Levels Change Assateague Island

Mercedes DeMasi has been coming to Assateague Island National Seashore to camp for more than 20 years.

She books her favorite spot, nestled in the dunes between the ocean and the island’s famous wild horses, months in advance.

But this year, she said, she noticed her spot doesn’t quite look like it used to. “Things have changed a lot around here,” DeMasi said. “I've definitely noticed like the dunes eroding a lot."

Kelly Taylor with the National Park Service said most visitors don’t really think about sea level rise here on the island until they can’t find their favorite campsite. “They're like, ‘Number 14 is the best site,’ and they turn around and are like, ‘Ah, what happened?’"

Sea level rise maps, like this one from the National Oceanic Atmospheric Administration, show why many call Assateague one of the most vulnerable national parks in the nation. NOAA tells the I-Team a mixture of ocean currents, thermal expansion and glacial melting means places like Assateague will see the water rise at least a foot – and as much as four to six feet - within our lifetime.

"It's been happening for a long time,” Taylor said. “Our heads in the sand until the last decade. So there's a lot of we're learning as we're going along."

Taylor explained how the island is moving, "rolling over" itself and migrating inward, wiping out not just campsites but parking lots and buildings as it goes.

She said after spending years -- and millions of dollars -- trying to force the island to stay the same, Assateague has become one of the first in the national park system to embrace rising sea levels.

The big wakeup call, Taylor said, was Hurricane Sandy. "The water came up so high that it basically undercut the parking lots. Huge chunks of concrete just basically fell over. We were like, 'This is silly.'"

The Park Service has now torn out some of the asphalt lots, moved them to higher ground and replaced them with cheaper clamshells, saving as much as a half-million dollars per lot each time a storm comes through.

The concession building that rents out bikes and kayaks has been replaced with shipping containers. “Literally less than 24 hours and that structure can be out of here,” Taylor said.

NPS also moved large buildings like the check-in station farther inland and onto pilings. “If we ever need to move this farther westward,” Taylor explained, “Then all we do is the big trucks come and lift it up off the piling and they can just kind of move it back. It just kind of makes sense to move with Mother Nature and to play her game."

But Mother Nature hasn't completely gotten her way on the northern tip of the island.

Justin Callahan of the U.S. Army Corps of Engineers said the Atlantic coastline used to stretch uninterrupted from Lewes to Chincoteague until 1933, when an unnamed hurricane ripped holes through the sand at Fenwick Island and Ocean City.

The Corps reinforced the new inlet at Ocean City with a jetty, but over the years scientists have realized the jetty catches large amounts of sand, creating a wider beach in Ocean City near the boardwalk while Assateague’s north shore erodes away and moves further and further inland.

"It could potentially wash away,” Callahan said. “That's where the Corps of Engineers project comes in."

The Corps spends more than a million dollars each year dredging sand out of the inlet system to replenish Assateague, helping to protect threatened and endangered seabirds like the piping plover that nest in the area, Callahan said.

"I think it's incumbent upon us to make sure that as long as this inlet system is maintained, as long as we create an unnatural interrupted sediment source, that we owe it to Assateague to take that material and put it back," Callahan said.

Back at the campsites, as old spots vanish beneath the moving dunes, they set up new ones, Taylor said. “We were in here the other day and were like, 'This is a lot better than what it was before.' So change isn't always a bad thing."

And that, she said, is the key. Making smart choices that let them roll with the island as it constantly changes so visitor's like Mercedes can keep camping here for another 25 years.

Reported by Tisha Thompson, produced by Rick Yarborough, and shot and edited by Jeff Piper.