Stormy seas churn up large whelk shells along the Outer Banks

Months of offshore storms and big surf are washing ashore some ocean treasures, including old and unusual lightning whelks.

Cape Lookout National Seashore says beachgoers have been finding large whelk shells on the beaches in recent days, including some “stained” by dark marsh mud found behind barrier islands.

A large lightning whelk found at Cape Lookout National Seashore over the weekend. [NPS photo]

“Since it was found on the ocean beach, this indicates that the island ‘rolled over’ it at some point in the past and the mud layer ended up being out in the ocean. The larger, stronger waves of the recent storms have unearthed both of these and brought them ashore,” the seashore said in a Facebook post.

The ocean has also unearthed some more scarce whelk shells. Knobbed whelks are common on Outer Banks beaches, but the lightning whelks are more unusual.

“The easiest way to tell the two apart is to look at the shell’s aperture (the opening for the animal) when holding the shell with the larger end upright. Can you easily put your left hand into the opening (see the top shell)? Then its a Lightning Whelk. Or does your right hand fit more easily (see the lower shell)? Then its a Knobbed Whelk,” the seashore wrote.

Lightning whelk versus knobbed whelk. [Photo courtesy Cape Lookout National Seashore]

This story originally appeared on OBXToday.com. Read More local stories here.