What Created the Carolina Bays?

Hundreds of similar-shaped ponds called the Carolina Bays pock the Eastern United States. Learn more about them in this episode of BrainStuff, based on this article: https://science.howstuffworks.com/environmental/earth/geophysics/carolina-bays.htm

Learn more about your ad-choices at https://www.iheartpodcastnetwork.com

See omnystudio.com/listener for privacy information.

Episode Transcript

Speaker 1 (00:01):
Welcome to brain Stuff, a production of I Heart Radio,
Hey brain Stuff, Lauren vogebon here. But when the Wright
Brothers gave us the engine powered airplane in the early
twentieth century, they didn't just give us a new way
to get around. A flight also gave us an entirely
different perspective on the things around us, or specifically, the
things below us. From above, people became tiny specks, and

(00:26):
fields looked like the tiled squares of a quilt, And
before long, on the East coast of the United States,
pilots began noticing something even more interesting. What we once
thought were just simple, isolated ponds and wetlands along the
Atlantic coast began to be seen as a pattern of
thousands of egg shaped depressions that were all oriented exactly

(00:47):
the same way. From above, it almost looks like a
giant from outer space sneezed all the way from Florida
to New Jersey, leaving a series of shallow depressions in
his wake. Their origins are still a scientific mystery today,
but these ponds are as important to the landscape now
as they were millions of years ago. Today, they're most

(01:07):
commonly referred to as Carolina bays, A large number of
them occur along the coast of North and South Carolina.
For the article, this episode is based on how Stuff
Work spoke with Kyle Barrett, Associate Professor of Wildlife Conservation
at Clemson University in South Carolina. He said, Carolina Bay
is the name given to most any wetland along the
eastern coastal plain that has an elliptical shape and is

(01:31):
often isolated from other bodies of water, such as small
streams or rivers. Carolina bays occur in low spots in
the landscape, and because they typically only fill up from precipitation,
they may dry out during the hot and dry portions
of the year. These elliptical pockets in the landscape are
almost always laid out with their long axis pointing northwest

(01:52):
to southeast, and it's common for many to cluster together,
so researchers in the nineteen fifties hypothesized that they were
the result of an ancient meteor shower. They've used carbon
dating and other techniques to determine their ages, but it
turns out the Carolina Bays were not all formed at
the same time. Some were formed tens of thousands of
years apart. Barrett said some wetlands are estimated to be

(02:16):
over a hundred thousand years old, whereas others may only
be fifteen thousand years old or less. There isn't any
support for this meteor shower idea since they don't have
the same origin date and no material has been found
in the soil to suggest extraterrestrial formation. The next best hypothesis,
while plus other worldly, is the most likely answer the wind.

(02:39):
It suggested that during the late Pleistocene period about two
and a half million years ago, very strong southwesterly winds
on ponds caused currents. Those currents washed against the southwest
and northwest sides of ponds and resulted in sediment deposits
on the northeast and southeast sides. Over time, they formed

(02:59):
what we now know as the Carolina Bays. At one
point there may have been as many as two hundred
thousand Carolina Bays, but researchers say that nearly of Carolina
Bays have been impacted by agriculture and logging. A human
impact hasn't just erased a piece of our geological past,
it's also disrupted a delicate ecosystem of marshes that are

(03:21):
important to many wetlands species like salamanders and frogs in
North America. Barrett explained, Carolina bays, along with other types
of isolated wetlands, offer a wide range of environmental benefits.
Many insects and amphibians are particularly abundant in these wetlands,
since Carolina bays are without fish most of the time.
Even terrestrial species such as birds and bats are more

(03:44):
abundant in patches of forest containing a Carolina bay than
equal sized forested areas without one. A Wetlands like the
Carolina Bays are also essential in preventing flooding and improving
water quality too. Unfortunately, many bays have been repurposed for
human use, like farmlands, the development of homes or businesses,
or expanded into ponds. Any wetlands that aren't near a

(04:08):
permanent stream or river, Barrett says, are not protected by
the Clean Water Act. Barrett said for this reason, if
you look at aerial imagery on Google Maps, for example,
you'll see loads of elliptical shapes along the coast of
the Carolinas that used to be wetlands but are now
filled in for agriculture. The result is that wildlife takes
on the burden of wetland loss. However, Barrett suggests an

(04:31):
expanded interpretation of the Clean Water Act could protect important
wetland locations, and he said, I don't know that every
isolated wetland needs to be federally protected. That seems like
it could create an unreasonable burden for many landowners. But
I do think a broader interpretation of the Clean Water
Act would help save many important isolated wetlands. The States

(04:52):
could also enact protections that better address local issues related
to wetland loss. Carolina Bays are just one exam bull
of Earth's natural mysteries that are important elements of our
North American ecosystem. When land is filled in for pasture
or crops, it doesn't just take away important habitats wetland species.
It also disrupts the balance of water flux and natural

(05:14):
flooding protections, which is bad for our homes and livelihoods too. Furthermore,
without these wetland habitats, we miss out on some of
the most biologically varied ecosystems in North America. Barrett said,
many people don't have an opportunity to see the incredible
amphibian and reptile diversity we have in the southeast, but
these wetlands, along with others in the region, are an

(05:37):
incredibly important home to these species. Visiting these wetlands can
open your eyes and ears when the frogs are calling
to some of the underappreciated gems of the Eastern Us.
One rare species, just for example, that inhabits the Carolina
Bays is twenty five different types of carnivorous plants. The
Carolinas are the only places where these insect eating plants,

(05:59):
like the sund and picture plant grow naturally. Today's episode
is based on the article what Caused the Mysterious Carolina
Bays on how stuff Works dot Com written by Allison Troutner.
Brain Stuff is production of I Heart Radio in partnership
with how stuff Works dot Com, and it is produced

(06:20):
by Tyler Playing. Four more podcasts from my heart Radio.
Visit the heart Radio app, Apple Podcasts, or wherever you
listen to your favorite shows.