How Climate is Changing Chesapeake Bay Shorelines for Archeologists, Paleontologists

Aug 2, 2016

Shorelines of the Chesapeake Bay are disappearing as sea level rises and higher tides eat away at beaches and cliffs. That means hand-wringing among some waterfront property owners. But for archeologists and paleontologists, the story is more complicated.

This summer, a team from Longwood University's Institute of Archeology in Virginia is mapping artifacts found on the western shores of the Chesapeake Bay and its tributaries. On a morning when the tide was supposed to be low, they found themselves in unfamiliar territory, wading along the Little Wicomico River amid empty shells of blue crab molts and stinging nettles. It didn't faze archeologist Craig Rose, whose next project is in the more familiar snake-infested woods of western Virginia.

“This is a pretty nice survey for sure. I've been doing archeology for a long time, and when all you have to worry about is jellyfish and sunburn, it's pretty good.”

And while the stinging nettles are bothersome, they've discovered something more problematic.

“So far, most of the shorelines we've encountered are either covered in rip rap or basically inaccessible. So we've only had one or two we could look at today.”

Longwood archeologists mapping along Little Wicomico River.

It's not just archeologists who are being affected by rising tides and increasing erosion. In Maryland, rip rap - the large rocks brought in to protect shores - is affecting the work of paleontologists like John Nance from the Calvert Marine Museum. On a hot July morning, he and a group of interns are below Virginia's Stratford Hall Cliffs wading through the Potomac River, peering up to see what the latest storms have exposed.

“People put piers in, erosion control, rip rap is the big one, all of that changes the dynamics of the beach. Along a number of the sections where we used to be able to collect where they've rip rapped, there's virtually no beach there unless it's a very low tide. It's one of the things we run into more and more frequently now.”

Rip rap is relatively new, says Prosser Crowther, whose family has lived for more than a century in Northumberland County, Virginia. His grandfather would cut trees along a river bank; let them fall into the water where they would become a groin to catch sand and dirt. His great-grandfather's generation didn't live on the waterfront.

“He has actually traded waterfront property for a team of oxen or a team of horses so that will give you an idea of how prized waterfront property was at one time, it wasn't, it just wasn't.”

Calvert Marine Museum interns and Paleontologist John Nance search Stratford Hall Cliffs along Potomac River.

Today rip rap, bulk-heading and other hardscaping are temporary fixes that will eventually give way to rising waters. Longwood archeologists looking for artifacts in the counties of Mathews, Middlesex, Lancaster and Northumberland have found Mathews is eroding the fastest, revealing the most artifacts. Archeological sites mapped during the project will be compared to aerial photographs from the 1930's to help the Virginia Department of Historic Resources and National Park Service determine those most threatened by rising sea-levels.

“How much longer these sites are going to be around. Some might be gone in five years and some might be gone in 200 years. So they're able to prioritize any future funding that they get to focus on the most threatened archeological sites.”

The team plans to use data collected from researchers around the bay who are doing similar work.