Storm waves along Outer Banks reveal large seashells long buried in dark marsh mud

OUTER BANKS, N.C. (Mark Price/The Charlotte Observer) - Cape Lookout National Seashore on the Outer Banks is seeing large seashells tumbling ashore, due to strong seasonal wave action off the North Carolina coast.

Park visitors report finding more shells than they can carry, and the park service says some of the shells could predate the current incarnation of the constantly shifting barrier islands.

Photos posted on Facebook show whelk shells found in recent days were nearly 13 inches long.

“Volunteers were on the beach when a wave carried the (largest) shell in and dropped it in front of them. How lucky can you get?” officials said on Facebook.

Lightning whelk shells are rare on the Outer Banks, where tourists are more apt to find knobbed whelk shells, officials said. However, both are prized by collectors and dealers. Whelk shells in the foot-long range sell for as much as $30 online.

National Park Service officials said bigger shells wash ashore this time of year as a result of “larger and stronger” waves from storms. “These larger waves are able to pick up and move the larger shells from the ocean floor, across the sand bars and onto the beach for us to find,” park officials posted on Facebook.

The Outer Banks are infamous for strange things washing ashore, including chunks of shipwrecks, World War II bombs and fossilized prehistoric seashells.

Darker whelk shells found at the park are old enough to have witnessed the barrier islands shifting over decades, if not longer, officials said.

The black color comes from being buried for extended periods in “dark marsh mud found behind the barrier island,” officials said.

Finding such shells on a beach can indicate “the island ‘rolled over’ it at some point in the past and the mud layer ended up being out in the ocean,” the park posted.