Effects Of Winter Road Salt Application And Episodic Pulses On Southern Appalachian Headwater Stream Macroinvertebrates

In many regions of the United States current winter road management operating procedures require that deicing agents be applied to roads before or during each of the winter snow and ice events. Boone, NC is unique because it has a winter climate comparable to southern New England due to its high elevation in the Southern Appalachian Mountains (982 m). Data collected from eight headwater streams with sondes from 2010-2015 (coefficient of variation of temperature, pH, and specific conductivity) and impervious/forested area determined by use of ArcGIS were correlated to NCDEQ Qual 4 benthic macroinvertebrate collections for which NC biotic index (BI), richness and Shannon diversity index were calculated. Variations in temperature throughout the seasons along with elevated specific conductivity levels had significant correlations and PLS VIP values with measures of stream health and diversity indicating a negative impact on macroinvertebrate communities. Additionally the impact of pulse NaCl exposure on aquatic macroinvertebrate survival was examined utilizing the most frequently experienced specific conductivity spikes (2,000 µS cm-1) and the worst case scenario spikes (10,000 µS cm-1) experienced in Boone Creek through the winter months from 2010-2015. Increased exposure to these levels cause decreased survivorship of larval Ephemeroptera Heptageniidae Epeorus and Maccaffertium spp.