Midwest Fish & Wildlife Conference 2018

AUTHORS. Matthew Altenritter, Andrew Casper - Illinois River Biological Station

ABSTRACT. Brandon Road Lock and Dam (BRLD) located on the lower Des Plaines River in Joliet, IL has been identified by the United States Army Corp of Engineers as a potential site for the implementation of aquatic nuisance species (ANS) control measures. Proposed structural control measures are intended to prevent the upriver movement of ANS such as silver and bighead carps through the lock chamber at BRLD. Subsequently, upriver movement by native fishes would also be prevented. Recent surveys of fishes inhabiting the Des Plaines River above BRLD, suggest upriver lockage has facilitated improvements in native fish community richness over time. Moreover, substantial investments in this area have been made to re-establish lotic connectivity providing increased habitat for newly arriving native immigrants. Increases in native fish community richness may also benefit mussel recruitment above BRLD. Our research aims to elucidate the consequences of hydrologic separation that is anticipated to truncate this migratory corridor for native fishes. By synthesizing and integrating available information into a conceptual model, we identify potential consequences of hydrologic separation affecting primarily fishes and mussels. We hypothesize that the loss of supplementary immigration of native fishes through BRLD will slow the rehabilitation of upriver fish communities and potentially limit mussel rehabilitation through vector truncation. We anticipate that our conceptual model will eventually serve to guide both future research priorities and mitigation efforts aimed at minimizing any negative outcomes of a hydrologic separation on aquatic resources upriver of BRLD.