Thesis Title

The Effect of Habitat on the Index of Biotic Integrity (IBI) in Bull Creek, Southwest Missouri


Jason Gunter

Date of Graduation

Summer 2002


Master of Science in Biology



Committee Chair

Daniel Beckman


The study was conducted in the Bull Creek drainage basin of the Missouri Ozarks between 1 June and 1 September, 2001. The goals of this study were to characterize the fish assemblages, evaluate specific habitat variables, and measure the index of biotic integrity (IBI), using fish assemblages as response to habitat variables. Physical habitat variables included mean wetted width, mean thalweg depth, mean canopy density, kilometers to the confluence of Bull Creek with Lake Taneycomo, temperature, substrate composition, and different types of fish cover. Fishes were sampled using backpack electrofishers, seines, and block nets from sixteen randomly chosen sites following standard IBI protocols, with the goal of collecting all fish within each site. Fishes were identified, counted, and returned to the stream when possible. The IBI scores for Bull Creek, on a 100 percent scale, ranged from 42 to 84, with a mean of 68, N=16, standard deviation=.1169, and standard error=.0292. The 95% confidence interval was approximately 61 to 73, ranking moderately impaired by our standards. The IBI was significantly correlated with substrate size, stream temperature, and canopy density.

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