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Rising Sea Adds Urgency To South Florida Archeological Digs

Archeologists working on an island just off Miami believe they’ve found a unique stone Indian burial mound. But with part of the site underwater, the team is battling a rising sea that threatens to cover the East Coast’s low-lying areas within the century.

It’s not easy to get to the dig site.

First, a 40-minute ride in a National Park Service boat ironically nicknamed Speedy.

Then, just off Totten Key, archeologist Josh Marano navigates the boat through a manmade channel cut from rocks that have shipwrecked lesser captains.

“You just really have to know the waters out here,” he says.

He ties the boat to some mangroves, jumps in the mud and trudges to shore. Rain boots are irrelevant here. The water is up to your thighs.

Then, it’s a kilometer hike through the woods on a roughly cut trail. Branches smack your face, and you have to limbo under root arches.

But Biscayne National Park Cultural Resources Manager Chuck Lawson says bringing archeologists out here is worth it.

“This is a really cool site. It’s one of the best ones in Biscayne,” he says.

He believes Tequesta Indians lived here until the Spanish occupation. In the mid-1980s, what he believes is the only stone burial mound in the country was discovered here, but no one’s excavated here since. Lawson says he’s recently seen parts of the site go underwater. Hurricane Sandy brought tides that submerged much of it. But after the water receded, he says federal recovery money offered the chance to do this work.

“The concern about it slipping away without any of that work being done has made me want to do this project for several years,” he says.

A small crew shovels soil onto a grate with quarter-inch holes, where they hand-sift it in search of artifacts.

One holds up a small blackish-brown object and asks, “Is that bone?”

“I think it’s bone, yeah,” answers another.

They’re digging on a huge pile of debris called midden. Lawson says it’s like a prehistoric garbage dump shaped into architectural mounds. The best modern-day analogy for it, he says, is a collection of beer bottles after a college party.

“Having a giant pile of shells outside your house shows just how big of a party you had and how much you gave away and raises your status,” he explains.

The mound slopes down into a mangrove swamp where the creek laps at it. How much is already submerged is unknown. Lawson says national parks along the East Coast are feeling the same pain.

“And every time there’s a storm, massive amounts of really significant amounts of archeological sites get lost into the ocean: I mean, 10-, 15-foot bluffs that are lost, whole mounds that are 20-foot tall,” he says.

Projects like the one in Biscayne Bay are expensive. And Lawson says the Park Service must decide which sites are most important and try to protect them or at least learn as much as possible before they’re submerged.

“What are we going to do? I don’t know. I guess we’ll do like the rest of Miami is going to do and figure it out when the water starts coming up. That’s what I’ll do when it starts coming up at my house,” he says.

But it’s already coming up. University of Miami Meteorologist Ben Kirtman says a warming planet has caused oceans to rise quickly. And he predicts South Florida to see another 6 inches in rise within the next 15 years. Without sea walls and pumps, like Miami Beach is building, Biscayne National Park could be in big trouble, he says.

“They’re just hoping that the water’s going to run off. So if you have a sea level rise of six inches, and a high tide at the same time and a big rain storm, they could be totally inundated,” he says.

At the Tequesta site, Lawson says the crew will work for a few weeks gathering artifacts. Then he might try to get funding to build a barrier to protect it.

“But there’s a lot of other sites all over the place that are not going to have those resources, so…they’re gonna go," he says. 

He’s planning a display for the park’s visitor center explaining whatever the team discovers at Totten Key—that is, as long as there’s a visitor center above water.