TRACKING HUMAN IMPACT IN APPALACHIAN CAVES: A MULTIDISCIPLINARY APPROACH

This project aims to explore and quantify anthropogenic inputs into caves from tourism across three caves in southern Appalachia: Daniel Boone Caverns in southwestern VA, Worley’s Cave in eastern TN, and Linville Caverns in western NC. Daniel Boone Caverns is closed to the public and is considered a “pristine” cave, Worley’s Cave is a wild show cave, and Linville Caverns is a developed show cave.

To assess the level of impact that tourism has on caves, we used a variety of analyses on cave sediments across all three caves: Illumina sequencing for microbial community structures, microplastics analysis, and transmission electron microscopy (TEM) to detect nanoscale human-made particles (which is the focus of this abstract). Sediment samples were examined from three caves from sites with varying traffic levels, using scanning transmission electron microscopy (STEM) to search for mineral grains that were inconsistent with what is typical for each cave environment. Undisturbed soil samples from outside the caves were also analyzed as a control.

Of particular note are the samples from Linville Caverns, the most highly developed of the three caves, which contained a variety of different human-made particles. These include potential coal ash, as well as some unidentified inorganic particles consisting of phosphorous particles within a potassium and sulfur rich matrix. Consistent with microbial sequencing and microplastic analyses that reveal a signature of human impact in show caves, TEM analyses of cave sediments reveals an abundance of human-made particles as well. This work contributes to our understanding of human impacts on cave environments, and demonstrates how tourism and recreational caving may impact sediment and microbial compositions within caves over time.