Ferrier, DrewOtt, Marie2020-11-202020-11-202020-11-18http://hdl.handle.net/11603/20112Road salt application is a common practice within the United States during the winter season. Depending on the intensity of the snow events, deicing amounts vary from year to year. The introduced sodium chloride from deicers causes stress within nearby stream communities, especially to the periphyton community, which is the basis of in-stream primary productivity during the winter season. To determine the salinity stress within the periphyton community, I employed pulsed amplitude modulated (PAM) fluorometry. During the 2016-2017 winter season, I measured the photosynthetic efficiencies of a natural lotic periphyton community within Carroll Creek in Frederick City, MD by monitoring community stress levels under various short-term laboratory salt exposures. Laboratory test results show a short-term negative impact to the photosynthetic ability of periphyton, with an increase in sodium chloride concentration. In addition, exposing the salinity stressed samples to fresh water marked a recovery in photosynthetic ability. Further research will be necessary to establish if there are long-term effects of increased salt concentrations within Carroll Creek in Frederick City.Attribution-NonCommercial-NoDerivs 3.0 United StatesPAM FLUOROMETRYPERIPHYTONSALINITYRoad SaltText