The use of nature-like fishways to increase ecosystem connectivity has risen in recent years. In 2009, a rock ramp was constructed in the Shiawassee River to replace Chesaning Dam, formerly located in Chesaning, Michigan. The objective of my study was to evaluate the effects of the rock ramp on the summer fish assemblage. To accomplish this objective, I sampled fish in three rivers in the Saginaw Bay watershed, the Shiawassee (rock ramp), Cass (dammed), and Flint (free-flowing) in 2011 and 2012. I compared patterns of fish assemblage characteristics found in the rock ramp river to patterns in the dammed and free-flowing rivers. All three rivers had high similarity in species composition between upstream and downstream reaches. Patterns of species richness by site, mean CPUE, and proportional abundance in the rock ramp river had a higher similarity to the free-flowing river, while species richness by reach and species' impact factors had higher similarity to the dammed river. My findings suggest that the rock ramp has increased ecosystem connectivity for the summer fish assemblage, overall having fish assemblage characteristics patterns with higher similarity to the free-flowing river then the dammed river.
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