The Project

The purpose of this research project is to compare riffle and snag habitats in streams to a determined true-annual BI value using variations of the modified BI as proposed by Hilsenhoff (1998). The different variations of the BI calculation (using 5, 10, 12, 15, 20 and 25 individuals of each arthropod taxa), and the mean tolerance value calculation (Lille & Schlesser 1994) will be statistically compared to each other to see if it would be possible to estimate the BI more accurately in snag habitats throughout the year using one of the modified BI calculations.

Samples have been collected monthly from Bearskin Creek in Oneida County Wisconsin, and will be analyzed together with data from 3 other central Wisconsin streams (Comet Creek, Spring Creek, and the Tomorrow River) previously collected by Ann Hooper (1993) a former graduate student from UWSP. Additionally, because Bearskin Creek is an important north central Wisconsin trout stream, this project will generate valuable information on water quality and invertebrate taxa for the DNR. The end result of this study may be a modification of the Biotic Index which would more accurately determine water quality during all seasons from snag habitats in streams where suitable riffle habitats are absent.