Subterranean Fishes of the World

6256

2023

113 pages

Mammoth Cave is an iconic example of the cave and karst systems that underlie over 50% of the United States and provide around 13% of the world’s population with water resources. These environmental features are vulnerable to drought, pollution, and human impacts. The complex hydrological regime of the Mammoth Cave system has been studied in the past, but there are improvements and updates that can be made to the past research. The dynamics of the surface-groundwater system, particularly reversals of the Green River and how it backfloods into the cave, are some examples. Echo River and River Styx Springs provide recharge to the Green River from the cave during normal flow, but can reverse under flood conditions. Gaining an understanding of how the groundwater level changes during these events within this system improves understanding of Mammoth Cave’s ecosystem, development, and future evolution. Data were obtained using water sampling, data loggers, geochemical and isotopic analysis, and GIS analysis. Results suggest complex hydrodynamic interactions between the Green River and both Echo and River Styx Springs, where hydraulic head within the karst system competes with that of the Green River during recharge events. When recharge volume is high in cave, the springs flow normally; however, heavy rainfall upstream or within the basins adjacent to the springs cause the Green to reverse flow into the springs and conduit systems, affecting temperature, isotopic variability, and dissolution dynamics

2