Great Smoky Mountains National Park Fisheries Index of Biotic Integrity (IBI) Surveys

These data represent an assessment of Ichthyofaunal community structure in selected streams located in Great Smoky Mountains National Park (GRSM). Sites are sampled on a rotational basis occurring once every two years. Currently (2020), there are ten watersheds being sampled using IBI protocols. Depending on the yearly rotation, these watersheds include Noland Creek, Deep Creek, Big Creek, Oconaluftee River, Eagle Creek, the East Prong of Little River (two sites), Straight Fork, Tabcat Creek, and Hazel Creek. In 2020, six sites were surveyed: East Prong Little River at Elkmont, Cataloochee Creek, Eagle Creek, West Prong Little River, Abrams Creek, and Oconaluftee River. Fish community assemblage assessments are made after collecting specimens using backpack electrofishing and seining techniques. Unlike the 3-Pass depletion method used to observe census data from GRSM streams, an IBI is used to determine how many species of fish are represented in a stream segment by surveying the various types of habitat: riffles, runs, pools, and shoreline. Techniques for IBI sampling also use seining in conjunction with electrofishing for fish capture. The point of IBI sampling isn’t to remove all the fish present, but rather to determine the community assemblage, i.e., species diversity within the stream segment. The GRSM Fishery Division works in conjunction with aquatics biologists at the Tennessee Valley Authority (TVA), who then provide “scores” regarding the species’ representation or robustness given the site criteria. IBI scores and metrics are determined using the TVA IBI Stream Survey Recording System v2.02. Once data have been entered by GRSM staff in the TVA Stream Survey database, results are sent to TVA biologists, who then provide GRSM with the scores associated with the species observed. These scores for 2020 survey data were provided to GRSM by TVA during Fall 2020.