GRANDFATHER MOUNTAIN, NC – Most people can say that at some point during their childhood they were on their hands and knees digging in the dirt or doubled over gazing into a stream. All had the same goal: catching a freshwater crustacean.
Whether you knew them as crayfish, crawdads or mud bugs, the excitement of catching one of these elusive critters on a hot day lives forever in your summertime recollections. Grandfather's naturalists are creating their own memories this season while collecting specimens and data to share with the North Carolina State Museum of Natural Sciences.
Chief Naturalist Jesse Pope and his staff of three are hoping to comb through every tributary on Grandfather this summer. The Mountain's crayfish have never been surveyed before, so the project's goals are to document what they find and to look for new species.
So far on their expeditions the team has sent 15 of the crayfishes collected to Raleigh. About the same number, or more, were released back into the wild because of their gender or size.
"We are looking for large, mature, adult males," said Pope. "While crayfish are maturing they have subtle differences in their appearance and therefore once they reach adulthood they are much easier to identify."
These subtle differences relate to their overall size, the size of certain body parts, differences in the color of their shading or spotting, or the length and shape of the claws.
Different species live in different kinds of habitat. Some live only in fast-moving streams, some can live only in calm pools, and another even burrows on land. Native to the upper Catawba River basin, the burrowing Cambarus dubius has already been spotted on Grandfather.
"This information will help rare and endangered species programs, water quality, biodiversity analysis, conservation planning, and biochemical systematics," said Research Curator of Crustaceans Dr. John Cooper of the N.C. Museum of Natural Sciences. "A great deal remains to be learned about the state's crayfish."
The major threats to freshwater crustaceans are habitat destruction, invasive species and pollution. They are particularly sensitive to cadmium and the other chemicals in certain pesticides.
All specimens gathered on Grandfather are sent to Cooper to be identified and assigned a catalogue number. This information will be entered into the general crustacean catalog which ultimately will be available in an electronic database for scientific reference.
"It's an honor to work with Dr. Cooper," said Pope. "Crayfish in this state are very under studied and he is one of the few experts that can identify the different species."
While Cooper is in the process of co-authoring a monograph on "The Crayfishes of North Carolina" with Suzanne A. Cooper, the Naturalists are busy flipping rocks on Grandfather.
Pope and his team use three different tactics for catching crayfish. For large streams they stretch out a large net from bank to bank. Weights are on the bottom of the net holding it down while the naturalists go a little upstream and begin flipping rocks. This technique causes crayfish to float downstream into the net.
When investigating a smaller stream or shallow water they use a kick net. This usually employs two or three people, one to hold the net just downstream from where the others are picking up large rocks and shaking things loose.
The third, and the best known to kids or kids-at-heart, is what Pope refers to as "stalking." The crayfish hunters flip over rocks, wait for the silt and sediment to clear and then see what they have uncovered. This process works best in streams with rocky bottoms, a frequent condition on Grandfather.
Once a crayfish has been spotted, Pope explains that his preferred technique is to press them against the bottom of the stream so they can't walk or crawl away. Finger placement and patience are key components.
"The crayfish are definitely hard to spot your first time out," said Naturalist Katie Gray. "With some practice, it gets much easier to see them in the water. We call Jesse the Crayfish Whisperer."
For each crayfish that they keep, the naturalists record the date it was collected, as well as the GPS coordinates and elevation where it was found. Crayfish range to about 5,000 feet in elevation.
Pope believes that the majority of the crayfish they are finding on Grandfather this summer are the common Cambarus bartonii, but he is eager to find the Grandfather Mountain Crayfish, Cambarus eeseeohensis, first described by Roger Thoma of Ohio State University in 2005.
"Roger first became aware of it in collections at Ohio State in 1978," said Cooper. "According to him, it's known only from the Linville River above Linville Falls, but that remains to be determined by thorough surveys throughout the upper Catawba basin and nearby streams of the Watauga basin, which also originate on Grandfather Mountain.
"In the past decade or so I've described a bunch of new species from the state, and I'm sure there are others out there awaiting discovery," said Cooper.
For more information on Grandfather Mountain and the staff naturalists please visit www.grandfather.com or call 800-468-7325.
