Tuberty, Shea.(1), Fleetwood, M. (1), Balcomb, J.(2), Cockerill, K.(3), Colby, J.(2), Gu, C.(4), Perry, B.(2), Swinson, B.(2), Cox, A.(1), Snow, C.(1), Tate, B.(1), Beyersdorf, K.(1), Chu, H.-M.(1), Davis, B.(1), Jones, W.(1), Lipinski, M.(1), McGlasson, M.(1), and Mouro, A.(1)
(1) Biology, (2) Geography and Planning, (3) Sustainable Development, (4) Geology, i
Appalachian State University, Boone, NC.

Freshwater organisms are at risk from exposure to elevated levels of salt due to runoff following winter road salt applications, mining spoil runoff, saltwater intrusion from the damming of coastal rivers, and rising ocean levels due to global climate change. It is estimated that chloride concentrations above 800 ppm are harmful to most freshwater aquatic organisms—because these high levels interfere with how animals regulate the uptake of salt into their bodies. In the town of Boone, NC (Watauga Co, elevation 1015 meters), based on the stream Cl- concentration and discharge observed at Boone Creek, it is estimated that about 770 tons of NaCl are applied annually to streets that runoff into Boone Creek basin. Climate records of winter snow falls were compared to data gathered from In Situ® water monitors installed at the outflow of seven headwater sub-basins of Upper South Fork New River. Data shows background conductivities of 30-50 uS/cm while episodic high conductivity stormwater pulses during and after winter storms reach levels as high as 7000-13,000 uS/cm (equivalent to salinities of 6.6-12.8 ppt) in the urbanized stream catchments. To determine the salt tolerance of benthic macroinvertebrates to these short term episodes of high road salt levels, acute toxicity tests were performed with local species of Ephemeroptera, Plecoptera, and Trichoptera orders at concentrations ranging from 300 to 13,000 uS/cm.