At the St. Croix National Scenic Riverway, researchers collected zebra mussel veliger samples from throughout the riverway and analyzed them to determine population and reproduction dynamics.
At the Apostle Islands National Lakeshore, researchers surveyed the area to determine the distribution and density of both quagga mussels and zebra mussels. Individuals of both species were collected and genetic analysis was conducted in order to determine the source populations. Researchers also sampled calcium ion concentrations to assess the potential for establishment and growth of invasive mussels. Lastly, researchers revisited native mussel beds that were surveyed in 1992 to assess changes of these sensitive native species in the face of invasive mussels, climate change, and other impacts.