Rapid Bioassessment of Crabtree Creek (Wake County, North Carolina) Using Macroinvertebrate and Microbial Indicators

ABSTRACT

Crabtree Creek, a relatively shallow stream in Wake County, North Carolina is a major tributary of the Neuse River, which has historically received much attention with regards to water quality and health concerns within the state. We undertook a preliminary survey of Crabtree Creek in an effort to assess the water quality and determine the ecological integrity of this drainage system. Data were obtained during spring, fall, and winter at seven sites along the creek. The substrate ranged from boulder to cobble, gravel, and sand with moderate to heavy sedimentation at many sites. Dissolved oxygen was not considered stressful to organisms, except at one location, and most chemical parameters fell within normal ranges. Coliform bacteria, detected at all locations, were especially high in four of the seven study sites. Overall, taxa diversity and richness were low, and the invertebrate community included few ephemeropterans, plecopterans, and trichopterans but had many other pollution-tolerant species. Depending upon the site and season, the biotic index suggested water quality ranged from very good to very poor.