Zebra, quagga, and native mussel research efforts on the St. Croix Scenic Riverway and Apostle Islands National Lakeshore

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.

Pilot work in Minnesota has shown that starry stonewort populations and growth patterns of can vary between years and between lakes in different locations. These patterns suggest that how starry stonewort invades a lake could be influenced by climatological factors such as ice-out date, growing season length, and average water temperature. If this is the case, then developing effective management strategies for starry stonewort requires a deeper and more specific understanding of how climate change will influence the invasion dynamics of the species. 

The project includes:

  • An empirical study of starry stonewort invasion dynamics in nine lakes across latitudinal gradients in Wisconsin, Minnesota, and Indiana.
  • Interviews with AIS managers and decision-makers in Wiscnsin, Minnesota and Indiana to examine invasive species management perceptions and preferences as they relate to starry stonewort.
  • Modeling starry stonewort invasion patterns under a range of climate and management scenarios. 

This project will provide practical information on the ecology of starry stonewort, a summary of current stakeholder preferences around starry stonewort management, as well as an evaluation of optimal management strategies.

The study is one component of a larger research project that is funded by the Prepared for Environmental Change Grand Challenge initiative administered by the Environmental Resilience Institute at Indiana University

Project manager: Mike McCartney

Funded by: National Park Service

Project start date: 2016

Project end date: 2018

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