Mercury and Marbles

As the Audubon Center at Francis Beidler Forest has noted previously in this blog, the fish in Four Holes Swamp are contaminated with mercury. The mercury is mainly generated by the burning of coal for electricity generation. The mercury exits the smokestack and settles in water systems across the Coastal Plain. Once in the water, bacteria convert the mercury into methylmercury, which is moved up the foodchain as larger fish eat smaller fish. Eventually, humans catch that big Largemouth Bass or Bowfin and ingest the mercury when they eat the fish.

The state's Department of Health and Environmental Control (DHEC) posts advisories regarding the consumption of fish from various rivers, lakes, and swamps, but there has never been a study regarding the effect of mercury on the state's citizens who consume the contaminated fish. The Post and Courier reported today that a study set to determine the effects, if any, of mercury-contaminated fish on humans has now had its funding reduced.

Today, we were visited by the Lowcountry Institute's Master Naturalist class from Spring Island. We didn't detect any mercury, but we found a group of animals that is declining around the globe. Habitat loss, environmental pollution, increased ultraviolet radiation, and disease are all factors in these amphibian population declines. What we found were several Marbled Salamanders (Ambystoma opacum) along with some Slimy (Plethodon glutinosus), Southern Dusky (Desmognathus auriculatus), and Three-lined (Eurycea guttolineata) Salamanders. Under one log, we found a female Marbled Salamander guarding her eggs. Hopping nearby were Southern Cricket Frogs (Acris gryllus), a Pine Woods Treefrog (Hyla femoralis) and a Southern Toad (Bufo terrestris).

Naturally, our camera was inavertently left in the car when the group consolidated into fewer vehicles for the arduous chore of unlocking and locking four gates along the access road to the bluff at Mallard Lake. Fortunately, there were numerous other cameras taking images and we were promised copies! We'll post them as they arrive.