General audience abstract from Caleigh's thesis submitted to her Master's Committee: 

"Surface coal mining operations in the Appalachian Coalfield region have resulted in decreased water quality and increased salt levels (measured as specific conductance; SpC) in small, headwater streams. Declines in aquatic biodiversity have been documented with increases in SpC, but little work has been done to address impacts on broader stream processes such as ecosystem metabolism, which represents organic carbon fixation and breakdown by gross primary production (GPP) and ecosystem respiration (ER), respectively. High stream flows are a known driver of both ecosystem metabolism and SpC concentrations in headwater streams; however, minimal work has been conducted to connect the roles of these interacting drivers (flow and SpC) on metabolism. This study measured metabolism across three headwater streams in the Appalachian Coalfield of varying salinity and flow regimes from August 2024 to August 2025. We found no relationship between ecosystem metabolism and SpC across our sites. Increases in GPP and ER at our high SpC site suggest a subsidy effect, although small sample sizes and the potential for increased light availability complicate this interpretation. While we found no consistent effect of SpC on metabolism across our sites, variation in flow-metabolism relationships from reference conditions at salinized sites suggests salts exhibit a potential effect on ecosystem processes. We encourage continued work on connecting ecosystem metabolism and freshwater salinization across flow regimes in headwater streams."