Integrity of benthic macroinvertebrate communitiesin Bluestone National Scenic River,Gauley River National Recreation Area,and New River Gorge National River: Eastern Rivers and Mountains Network 2009 summary report

Tzilkowski, Caleb; Callahan, Kristina; Marshall, Matthew; Weber, Andrew

During 2008, the Eastern Rivers and Mountains Network (ERMN) of the National Park Service (NPS) began monitoring benthic macroinvertebrate (BMI) communities in wadeable streams throughout its nine parks. There were 26 randomly selected sites and seven "targeted" (i.e., non-random) sites sampled throughout Bluestone National Scenic River (BLUE), Gauley River National Recreation Area (GARI), and New River Gorge National River (NERI) during March and early April 2009. In addition to BMI samples, core water quality data (i.e., temperature, dissolved oxygen, pH, and specific conductance) were collected and reach-scale habitat was characterized.Core water quality parameters at BLUE, GARI, and NERI sites were typical of forested watersheds with similar geologic characteristics. Relationships among core parameters were also typical – specific conductance generally decreased with decreasing pH. The pH of BLUE, GARI, and NERI streams ranged from 5.59 (Richlick Branch) to 8.58 (Arbuckle Creek), but the vast majority of sites had pH between 7.00 and 8.00. In addition to having high pH (8.53), water at the Bluestone River sites had, by far, the greatest specific conductance (≈ 425 μS/cm) of any of the sampled sites.Benthic macroinvertebrate communities throughout BLUE streams had Macroinvertebrate Biotic Integrity Index (MBII) values that ranged from 34.1 (Mountain Creek) to 48.5 (Bluestone River [Tramway]). Based on MBII thresholds for the Southern Appalachians Ecoregion, none of the sampled BLUE sites were considered to be in the "Good" condition class. One site (Mountain Creek) was estimated to be in "Poor" condition whereas the remaining three sites were in the "Fair" condition class. At GARI, all stream condition classes were represented among sampled streams; each class was represented by one stream. Based on the MBII, Horseshoe Creek ranked highest (MBII = 54.2), followed by Meadow Creek (46.5), and then by Laurel Creek (34.0), which was considered to be in Poor condition. Benthic macroinvertebrate communities throughout NERI had MBII values that ranged from 16.3 (Wolf Creek) to 73.7 (Laurel Creek). There were eight NERI stream sites considered to be in Good condition, 11 sites were in Fair condition, and 6 sites were in Poor condition.Based on the probabilistically chosen sites, distribution of wadeable GARI and NERI streams among condition classes was better than streams throughout the ecoregion as reported in the U.S. Environmental Protection Agency’s Wadeable Streams Assessment (WSA). As detailed in the report, methodological differences between the ERMN and WSA likely led to underestimates of BLUE, GARI, and NERI stream condition. What this means is, in the framework of the WSA, ecological integrity of GARI and NERI wadeable streams was likely even greater than we estimated during 2009. With each future sampling season, the ERMN BMI monitoring program will be refined and improved, which will allow more precise and accurate comparisons to be made among BLUE, GARI, and NERI streams and streams throughout the region.

Integrity of benthic macroinvertebrate communitiesin Bluestone National Scenic River,Gauley River National Recreation Area,and New River Gorge National River: Eastern Rivers and Mountains Network 2009 summary report

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