Field evaluation of carbon dioxide as a fish deterrent at a water management structure along the Illinois River
Construction of a water management structure (WMS) in the levee surrounding The Nature Conservancy’s Emiquon Preserve (Havana, Illinois, USA) created a new hydrological connection and potential aquatic invasive species pathway between the Illinois River and a large conservation wetland complex. Site managers need a control tool that deters the upstream passage of non-native fishes into the wetland lakes, but does not interfere with normal gate operation and water discharge. This short field study evaluated carbon dioxide (CO2) injected into water as a non-obstructive method to reduce fish abundance near the WMS culverts. We quantified relative fish abundance using underwater sonar with and without injection of CO2 into culverts during three discharge events: no flow (0 m3/s), restricted flow (0.9 m3/s), and unrestricted flow (3.2 m3/s). Overall, CO2 reached or exceeded our target concentration of 100 mg/L during no flow and restricted flow, and fish abundance was 70–95% lower at culvert entrances relative to untreated control days. The target CO2 level was not reached during unrestricted flow and fish abundance was not reduced during CO2 injection. Atmospheric CO2 concentrations were inconsequential and unaffected by CO2 treatments throughout testing. Results from this initial field study provide several considerations for CO2 as a fish deterrent in natural environments.
Additional publication details
|Publication Subtype||Journal Article|
|Title||Field evaluation of carbon dioxide as a fish deterrent at a water management structure along the Illinois River|
|Series title||Management of Biological Invasions|
|Contributing office(s)||Upper Midwest Environmental Sciences Center|
|Other Geospatial||Illinois River|