Carolina Bays

South Carolina’s Mysterious Wetlands

Carolina Bays are a unique terrestrial formation along the Atlantic coastal plains that, many believe, find their roots during the post glacial era.  Over the past forty years, scientist and naturalists have discovered that these formations have created a ‘time capsule’ of rich biodiversity that often include rare and endangered species of plants, and refuge for similarly dwindling species of animals.

So, what is a Carolina Bay?

A Carolina will typically share most if not all of the following characteristics:

  • Oval shape
  • NW (top)– SE (bottom) orientation
  • Parallellxm of axis (narrow & long)
  • Sand rims raised above surrounding ground general level
  • Interior surfaces below the surrounding ground level
  • Differences between their interior soils those in the surrounding areas
  • Relatively shallow depths
  • Flat sandy bottoms beneath their interior fill
  • Apparent independence of inflowing or outflowing streams

At the conclusion of a study by the SC Heritage Trust from 1983-1988 a study was published in which determined that there were 2,651 bays in 29 counties of South Carolina with an axis greater than 416 feet.  613 of those were selected for field study, and 219 of those determined to be relatively intact with minimal disturbance.  Thirty-six of those were selected for SC Heritage Trust conservation projects.  In a 1999 study published by the SC Dept of Natural Resources they advanced a recommendation to the US Environmental Protection Agency for 109 of those areas for protection.

 A Brief History:  Ancient & Modern

In 1765 William Bartram and his son John travelled along the Atlantic coastal plain and in the publication of the trips ‘Travels’ journal in 1791 is perhaps the earliest recorded description of the Carolina Bay.  In 1848 state biologists Michael Tuomey was the first to note their distinctive shape.  But it wasn’t until the 1980’s that a USDA aerial photography program gave us an order of magnitude for these formations, and perhaps coincidentally the publication of John Bartram’s ‘Pocasins’ book in 1982 may have contributed to the timing of the ‘The Carolina Bay Project’ in 1983 by the SC Heritage Trust Program to study them.

Many scientists agree that the Carolina Bays likely began over 11,500 years ago during the post-glacial Wisconsin period.  As the frozen ground thawed, the wave action of melting water driven by the northwesterly winds of the period, formed these unique elliptical depressions. Other more colorful explanations include formation by sea currents from when the land was under the oceans, or the upwelling of water or siliciclastic karst formation, and even extraterrestrial impact hypotheses.  It makes for an interesting read and Wikipedia offers an impressive summation and exhaustive bibliography that makes for interesting reading.

A Rich Biodiversity Trapped in Time

During the 1980’s study, 36 plant species ‘of concern’ were identified, including 23 that threatened or endangered.

The fact that these bays today are typically impenetrable shrub thickets and often considered “snake-and-insect-infested-swamps” have conspired to deter most people, and even naturalists from investigating them.  Only in the last forty years have we begun to log an inventory of the incredible flora and fauna hidden in these habitats and begun to value them for the time-capsule treasures that they are.

The South Carolina Native Plant Society is pleased to have acquired two such Carolina Bays:

Kingsburg Bay

Lisa Matthews Memorial Bay

 

We invite you to learn more about these amazing projects by clicking on the photo above to the adjoining pages, and to participate in this incredible opportunity to restore and preserve these unique geomorphic enclaves of biodiversity in our state.

To make a contribution to either or both SCNPS Carolina Bay projects, please click here:
MAKE A CONTRIBUTION
Photo Credits:
Feature photo:  Carolina Bay complex in SC, courtesy of Geosciblogspot.com, originally from Georgia Southern Univ video

References:

  1. SC-DNR Advance Identification of Carolina Bays for SC  https://www.dnr.sc.gov/wildlife/docs/CarolinaBays.pdf
  2. Distribution and Status of Carolina Bays in South Carolina (Bennett & Nelson) 1983 https://www.dnr.sc.gov/wildlife/docs/CarolinaBaysStudy.pdf
  3. Wikipedia ‘Carolina Bays’  https://en.wikipedia.org/wiki/Carolina_bays