An Evaluation of Carbon Dioxide and Water Flow as Control Techniques for the Invasive Red Swamp Crayfish

Abstract

The Red Swamp Crayfish (RSC) is an invasive crayfish species that has invaded many water bodies in North America and other continents. Recent work has demonstrated the potential of carbon dioxide (CO₂) as a tool to drive crayfish out of invaded ponds, or to push them towards low CO₂ areas for increased capture. Additionally, these studies showed that there was a relationship between crayfish behavior and the presence of water flow. Due to the need to evaluate new control techniques for RSC, we estimated the number of crayfish that moved to a low CO₂ concentration refuge or emerged from the water surface in both field and lab studies. Additionally, we estimated the number of crayfish that moved towards a small area with water flow in it with field and lab studies. Results suggested that CO₂ did not cause crayfish to move to a lower concentration, however, crayfish exposed to CO₂ were more likely to emerge than crayfish in control settings. Water flow attracted RSC in a lab setting but not in a pond setting.