Assessment of Macroinvertebrate Communities and Food Availability for the Larval Eastern Hellbender Salamander (Cryptobranchus alleganiensis) in Northern Georgia

Macroinvertebrates are indicators of stream health and environmental change, and form complex communities in aquatic ecosystems. In addition to their role as indicators of stream health, they also provide a valuable food source for many juvenile salamanders, including the Eastern Hellbender (Cryptobranchus alleganiensis), a species of special conservation concern in Georgia. Therefore, macroinvertebrate diversity is not only an essential indicator of stream health, but also provides additional information on food availability for larval hellbender salamanders, a largely unknown life history stage for the species. We sampled during July of 2016, and report on the Ephemeroptera, Plecoptera, and Trichoptera (EPT) richness and diversity of macroinvertebrate communities in Georgia Appalachian streams that were concomitantly monitored for Eastern Hellbender populations. Over 1,200 macroinvertebrates were collected and identified from four streams in Georgia’s Toccoa River basin. These specimens were keyed out to the lowest taxonomic level possible in order to provide a macroinvertebrate profile for streams with stable, healthy hellbender populations with confirmed gilled hellbender larvae. Macroinvertebrate communities comprised over 29 genera across a wide range of functional feeding groups, with biotic indexes indicating both high diversity and high water quality. EPT richness index and percent EPT were also extraordinarily high across all sampled streams (15–21 and 66.1–89.5%, respectively). This macroinvertebrate profile suggests that the larval Eastern Hellbender salamander populations in these streams have diverse macroinvertebrate prey species available to them. This research provides insight into the association of larval Eastern Hellbender populations with macroinvertebrate communities, and can be used by conservation managers to inform preservation of the natural integrity of Appalachian streams