Comparison of Groundwater Chemistry And Associated Biodiversity of Sulfidic Karst Habitats in Southcentral Kentucky

In most ecosystems, primary production is conducted by plants or photosynthetic microbes; however, extremophilic sulfur-oxidizing bacteria can use hydrogen sulfide gas (H2S) as an electron donor to produce metabolic energy in a type of metabolism called chemoautotrophy. These ecosystems are a prominent feature of some karst landscapes, and two have been observed in the Mammoth Cave system, Sulphur River in Parker Cave and Marianne’s Pass in Mammoth Cave National Park respectively. Sulfidic water is ubiquitous in southcentral Kentucky and is strongly associated with hydrocarbon deposits. This oil boom of the 1880s in this region predates most environmental regulation and records of oil and gas drilling; abandoned oil wells abound and have been speculated to be the source of H2S in Parker Cave, but this is pure conjecture. Analysis of water chemistry at several sites along the structural monocline believed to supply Parker Cave with H2S brines will lead to a greater understanding of its source. Surveying biodiversity at Marianne’s Pass can lead to a greater understanding of productivity and trophic structure there