Comparison of two rivers i northern Michigan for determination of differential effects of development.

Abstract

Two rivers in Northern Michigan, one with and one without watershed development, were chosen for comparison of several health and diversity indicators. A bioassay was used to determine nutrient limitation, and sampling was conducted of water chemistry, riverbed habitat type and macroinvertebrate community. Nitrogen and phosphorous co-limitation was found in the more developed watershed, while nitrogen limitation was found in the undeveloped watershed. Macroinvertebrates were found to have a lower EPT index in the more developed watershed. The data revealed key confounding factors related to underlying geology, but a correlation between watershed development and measurable river effects was determined.