Joint research project studies genetic structure of Quagga Mussel population in southwestern United States

Written by: Peter Soeth

Invasive mussels colonizing on various items.
Invasive mussels colonizing on various items.
Quagga mussels have infested the southwestern United States after being first identified in Lake Mead in 2007. Since then the species has spread throughout the Colorado River, from Lake Powell to Imperial Dam. To help inform control and management strategies, Reclamation and the U.S. Army Corps of Engineers recently published a scientific paper "Patterns of Genetic Structure Among Invasive Southwestern United States Quagga Mussel (Dreissena rostriformis bugensis) Populations" in The Southwestern Naturalist.

"The intended results of control measures may be impacted by the information learned from this study on population genetic structure," co-author Sherri Pucherelli said. "While we learned a lot from this study, we will continue to monitor the genetic diversity to help inform future management strategies."

The study found that there were no significant differences between populations of quagga mussels in the southwestern United States. The results show a well-mixed, undifferentiated set of quagga mussel populations along the Colorado River. All seem to belong to a single genetic cluster.

It also found that the western mussel populations may be isolated from the eastern United States due to the geographical distance, unconnected watersheds and state watercraft inspections that are taking place throughout the west.

The research was funded by Reclamation's Research and Development Office and the U.S. Army Corps of Engineers Aquatic Nuisance Species Research Program. To learn more about the study, please visit

Published on June 04, 2019