The Laurentian Great Lakes have been greatly impacted by introduction of invasive species. The amphipod ‘scud’ (Apocorophium lacustre) has recently spread throughout the Mississippi River Basin and is now within 100 river kilometers of the Great Lakes. Based on its proximity to the Great Lakes, the high densities that it reaches, and its potential ecological harm, A. lacustre is a species of particular concern for further spread. There are no known barriers to the spread of A. lacustre from their current range into the Great Lakes, although the effect of the existing electric barriers, and of potential carbon dioxide (CO2) barriers, on macroinvertebrates are unknown. Our study evaluates the potential of electric and CO2 barriers to prevent further spread of A. lacustre. We constructed lab-scale electric and CO2 barriers and tested the effectiveness of these barriers in limiting amphipod movement.
Results/Conclusions
For each barrier we tested the effect of short-term exposure to simulate the scenario of scud being transported through barriers on a barge. Amphipods were introduced to a tank with either an electric barrier or CO2 barrier and then exposed to a range of voltages (106-424 V) or CO2 concentrations (100-600 mg/L CO2), and monitored for distinct changes in behavior. Preliminary results from the electric barrier on other macroinvertebrate species suggest that at a threshold of 106 V organisms experience functional incapacitation. We anticipate presenting results regarding the effects of these barriers on A. lacustre. Our study provides the first data regarding the efficacy of the existing electric barriers and of potential CO2 barriers to limit the further spread of A. lacustre and other amphipod species in the Chicago Area Waterway System and the Great Lakes.