Quantifying the Effect of Sampling Gear and Effort on the Index of Biotic Integrity in two Huron-Erie Corridor Areas of Concern

The Detroit and St. Clair rivers were identified as Areas of Concern (AOC) in response to losses in critical fish and wildlife habitat. Implementation of remedial action plans required aquatic monitoring of AOCs using the Index of Biotic Integrity (IBI), a multi-metric index for biological assessment. In this study, three methods of calculating the IBI were applied to fish communities sampled using two different gears to determine the influence of scoring and sampling methods on IBI scores. IBI score variance between sites was also examined to determine the influence of sample effort. The results revealed that the IBI was not sensitive to gear type in either rivers due to varying catchability of species for each gear type. No significant difference was found between the three methods of IBI calculation. IBI score variance determined that current sampling protocols reduce the variance of mean IBI scores within a river by ~75%.M.Sc