Carolina Bays

Nobody knows how Carolina Bays were formed. They look like swamps and wetlands from the ground, but from the air they take on a mysterious uniform shape and directional alignment.

LAKE WACCAMAW — Piloting his boat across the 9,000-acre lake, Toby Hall can’t get enough of Lake Waccamaw.

“This is a very, very special place—a unique place, a beautiful place,” Hall yells, over the sound of wind and waves crashing against the bow.

As a ranger and the park superintendent, Hall protects and preserves Lake Waccamaw and the state park around it. And he can list the many reasons the Columbus County jewel and tourist attraction is also an environmental treasure.

“Most of your Carolina Bay lakes don’t have the type of biodiversity that you find here,” explains Hall. “Your total species of fish—54 species—in a natural water system is incredible. There are also 15 species of mussels and clams. It’s so rich.”

But it’s a lot more than just biodiversity that makes this place special. It turns out Lake Waccamaw is a Carolina Bay, and Carolina Bays are a geologic mystery. Nobody knows how the features were made. More on that in a moment. First, let me explain the term Carolina Bay. In this case, it has nothing to do with a body of water on the coast. The word “bay” refers to the bay tree.

In fact, there are three trees that grow around a Carolina Bay: the Loblolly Bay, the Sweet Bay and the Red Bay.

"Carolina Bays are all considered wetlands,” explains Jerry Reynolds, an expert on Carolina Bays and the Senior Manager of Outreach at the North Carolina Museum of Natural Sciences. “Some of the bays are water filled and some are wet part of the year, but they are all technically wetlands, and the bay tree is a species of the wetland.”

Even more important is that the Carolina Bays are extremely diverse habitats for both plants and animals. During times of drought, the Bays become a refuge for plants and animals.

“These are extremely valuable because the Carolina Bay and Pocosin habitats have a deep rich soil, which creates a great diversity of shrubs, trees, and pilcher plants around the edges,” explains Andy Wood, Director of the Coastal Plain Conservation Group. His organization helps to preserve Carolina Bay habitats.

“And all of those combine to form habitat for birds, frogs, salamanders turtles—the great diversity of plants begets a great diversity of wildlife,” Wood adds.

Carolina Bays - Aerial ViewBut it is only when Carolina Bays are seen from the air that you discover what makes the features so unusual.

Reynolds shows images of Carolina Bays on his computer. On one image after another, elliptical shapes are seen on the ground. Large and small, in greens, browns and blues, the features are all over the countryside. Think of elliptical-shaped raindrops splattering on the pavement. Reynolds stops to explain one image.

“This is southern Cumberland County and north Bladen County, and as I zoom in you start seeing these features show up,” Reynolds explains as he rolls the wheel on the computer mouse.

“You can see they are all elliptical shaped, all oriented from northwest to southeast, and they all have a sand rim on the south side,” Reynolds says, gesturing to the features. “Some are water filled and some are filled with trees but these are all bays. And you can see they vary tremendously in size.”

But the bottom line is, even though the bays vary in size and in what they are filled with, they don’t vary in shape and orientation. That’s what makes the feature a Carolina Bay.

There are thousands of Carolina Bays stretching from New Jersey to Florida. The greatest concentration is in North and South Carolina. How the bays were created is a mystery, but there are theories.

The first is that subsurface limestone deposits gave way to sinkholes. Some researchers speculate that meteorite showers striking the earth caused the depressions in the sand. There’s even talk of giant schools of fish excavating depressions with their tails on the ocean floor for spawning, at a time when oceans covered the region.

Because there is no clear evidence supporting any one theory, all are possible. But the most likely reason for the creation of Carolina Bays is called Wind Oriented Lakes. In other words, the lakes were carved by the wind.

It suggests that as the oceans retreated from covering the coast, large pools of water remained. Strong winds, and the waves flowing north-northeast that were created, carved and elongated the ponds into their present shape.

It’s the most likely scenario. But that hasn’t stopped many other theories from being proposed.

“What about aliens?” I ask Hall. 

“Well, aliens is a theory,” Hall admits. “It’s not a high probability but that’s why we call them theories!”


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