A Comparison of Larval Fish Production in the Lower Red Cedar and Chippewa Rivers with Special Focus on the Percidae Family of Fishes

Abstract

Management of riverine fishes has become increasingly difficult as our waterways are subject to anthropogenic change. Moreover, when changes in fish communities occur, it is sometimes difficult to quantify them and approximate causes. The lower Red Cedar River and lower Chippewa River of western Wisconsin are no exception as these waterways have been modified since logging operations opened the region. The resulting dams and impoundments have elicited different outcomes. The lower Chippewa River is subject to incision while the lower Red Cedar suffers from algal bloom spillover via upstream reservoirs. Here, we sought to ascertain differences in fish reproduction between the two rivers and to generate questions for future investigation. This effort was motivated, in large part, by a previous survey on the lower Red Cedar River that indicated abundance of a signature species, the shovelnose sturgeon. In the time since the survey, this species has apparently declined precipitously, and it is unknown whether they still reproducing successfully in either river. To answer this question, approximately 2,400 larval fishes were collected over a two-year time frame. No larval shovelnose were observed while there were subtle differences in the larval community between rivers. Caveats are identified and future actions are suggested.