Correlations of Watershed Housing Density with Environmental Conditions and Fish Assemblages in a Tennessee Ridge and Valley Stream

ABSTRACT

We examined relationships of watershed housing density with instream environmental conditions and fish assemblage attributes in Mountain Creek, a third-order Ridge and Valley stream in Hamilton County, Tennessee (Chattanooga area). Habitat features and fish assemblages were sampled in May-June 2005 at seven sites (drainage areas <17 km²) in the middle-upper reaches of the Mountain Creek system (Tennessee River drainage). Watershed housing density upstream of the sites ranged from 49 housing units/km² to 72 housing units/km². Twenty-two fish species and 3,686 individuals were found at the seven sites. Native species richness per catchment area ranged from 1 species/km² to 6 species/km² at the individual sites. Index of biotic integrity (IBI) ratings varied from poor to fairlgood. Housing density was directly correlated with stream temperature, variation in discharge, fine sediment depth, and abundances of introduced and tolerant species; it was inversely correlated with dissolved oxygen, pH, variation in depth, substrate diversity, and native species richness. Although pockets in upper Mountain Creek appeared moderately healthy, most reaches exhibited signs of degradation. Catchments with > 60 housing units per km² (four of seven sites) received IBI ratings of poor or poorlfair. Our results underscore the negative effects of residential development on water quality, hydrology, habitat complexity, and fish assemblages in a suburban stream.