Fish Community Impacts of Low-Head Dam Removal in the Menomonee River, a Tributary to Lake Michigan, Milwaukee, Wisconsin

The Menomonee River watershed covers sections of four counties: Washington, Ozaukee, Waukesha, and Milwaukee encompasing 136 square miles and culminating in a 32 mile long river that flows into Lake Michigan at Milwaukee. The population density in the Menomonee River watershed is 2,337 people per square mile.  The Milwaukee Metropolitan Sewage District (MMSD) is undertaking a river restoration project whose goal is to improve river connectivity and fish access to upper portions of the river that have been blocked by dams as well as other concrete structures and channeling.  This will allow once prevalent, but now scarce species, access to extremely valuable areas for spawning.  This study is in the process of evaluating impacts on the fish community of removing three low head dams in the mid section of the river.  As part of this study evaluates potential impacts of a nuisance invasive species, the round goby, Neogobius melanostomus,  on the upper portions of the river.  The fish community is being sampled by electrofishing following fish IBI protocols.  In addition, diet overlap of the round goby and a native substrate feeder the blacknose dace, Rhinichthys atratulus, were assessed to predict potential impacts of opening this watershed to Lake Michigan fishes.