Thursday, March 26, 2009

Watershed Event

How many rivers are associated with the Four Holes Swamp watershed, which contains the Audubon Center at Francis Beidler Forest? Can't think of one? Then you are a winner! The Santee River flows north of Four Holes Swamp and is dammed to form Lake Marion. The Edisto River flows south of the Four Holes Swamp watershed and receives all the water that exits the watershed. The water in Four Holes Swamp is nearly 100% rain that has fallen at some point within the watershed boundaries.

Yesterday, we participated in the Charleston Air Force Base's Earth Day celebration. We brought bottom samples taken from the swamp near #5 along the old-growth swamp boardwalk. Many only see leaf litter on the bottom when they look through the slightly-tinted water of the swamp. However, the bottom is teeming with animal life. Some of those animals are eating the settled organic material that was not swept away by the swamp's flowing water. Other animals, like the predatory dragonfly nymphs (see image), are eating other animals. No matter what they are eating, some of the animals cannot tolerated pollution in the water, while others can basically live in sewage. By examining the percentage of pollution-intolerant species to the total number of animal species collected in the sample, we can tell qualitatively whether the water is high-quality or low quality.

Twelve fifth grade classes (300 students) from local Charleston County schools cycled through the Francis Beidler Forest tent and picked through sample trays. They used a dichotomous key to identify dragonfly nymphs, crayfish, snails, mussels, mayfly nymphs, scuds, and various worms and smaller organisms. It is always a high-interest activity and the quarterly samples we take continue to show that the water in Four Holes Swamp is of the highest quality!

Today, the Master Naturalists from Spring Island (near Beaufort) visited to study the cypress-tupelo swamp habitats and the associated limestone bluff habitats. Although the day did not warm terribly, we did see two Banded Water Snakes, two Eastern Cottonmouths, the alligator, a Common Snapping Turtle in search of a mate, a River Frog, a Green Treefrog, a Great Egret, a Great Blue Heron, numerous Northern Parula Warblers, a Belted Kingfisher, and a Barred Owl catching and eating crayfish. We talked about the impending start of Project PROTHO, but did not detect any Prothonotary Warblers along the boardwalk.

Along the bluff, we discovered a Southern Dusky Salamander (Desmognathus auriculatus) and a Three-lined Salamander (Eurycea guttolineata) within the seeps coming from the bluff. We also saw Red Buckeye (Aesculus pavia), May-apple (Podophyllum peltatum), and Jack-in-the-Pulpit (Arisaema triphyllum) blooming.

Another great day in the old-growth swamp!

Images by Mac Stone

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