Water quality and atmospheric carbon dioxide data for field application of carbon dioxide during summer 2018 as a behavioral control method for invasive red swamp crayfish (Procambarus clarkii) in southeastern Michigan water retention ponds.

This study evaluated carbon dioxide (CO2) injected into water as a possible behavioral stimulant to enhance capture and removal of invasive red swamp crayfish (RSC, Procambarus clarkii Girard, 1852) from a retention pond in southeastern Michigan. Objectives of this study were to (1) determine if target CO2 concentrations were attainable within the infested pond, and (2) determine if CO2 treatment was effective to push RSC towards shorelines or onto dry land where they could be collected and removed. Carbon dioxide was applied directly into one treatment pond (~2,500 m3) in Novi, MI. Two nearby ponds in Livonia, MI were used as untreated control ponds. Crayfish removal efficiency was evaluated in all ponds using baited traps and shoreline surveys. Results showed that the CO2 treatment pond reached its target concentration of >200 milligrams per liter (mg/L) CO2, a benchmark determined from previous laboratory studies, approximately 11 hours after injection started and was maintained between 200-351 mg/L CO2 for approximately 2.5 days. During treatment, some emergent crayfish were observed near influent culverts around the pond, possibly indicative of a behavioral response. However, the number of individuals and crayfish observations were minimal and infrequent. Crayfish continued to be removed throughout CO2 treatment with baited traps and perimeter surveys, but differences in catch rates between the treatment and control ponds were not apparent and confounded by a temporal decline in catch rates across all ponds. Overall, this study demonstrated that open-water treatment applications with CO2 are possible, but its effectiveness to enhance RSC removal was unclear due to limited crayfish observations.