Invasive quagga mussels can be attenuated by redear sunfish (Lepomis microlophus) in the Southwestern United States

The degree to which invasive quagga mussels have spread across the Southwestern United States is unprecedented, and until now, none of the controls currently available is risk-free to the environment or human health. Here we demonstrate that stocking high-density (0.42 fish/m³ or 1.90 fish/m²) redear sunfish (Lepomis microlophus) in an infested lake enclosure removed adult quagga mussels efficiently and appeared to suppress their growth and recruitment. However, mussels were not eradicated during the short term experimental course. Long-term study needs to be conducted to determine whether mussels can be completely eliminated by redear sunfish and what optimum density would be required for balancing high efficacy mussel control with cost-effectiveness. Redear sunfish is a species native to the Southeastern United States that has become a popular, stocked sportfish in the Southwest. Targeted stocking of redear sunfish may be an efficient and environmentally friendly approach to mitigate the colonization of invasive quagga mussels in suitable open water ecosystems, especially those with new dreissenid infestations or those threatened by invasion.