Recognizing high-risk areas for zebra mussels and Eurasian watermilfoil invasions in Minnesota
The early detection of invasive species such as zebra mussels and Eurasian watermilfoil is crucial to the success of control efforts. However, detecting these species early can be very challenging due to several factors, such as the absence of a surveillance program, relying on public reporting, and limited resource availability, which can result in reporting bias and underreporting.
The goal of this project was to improve the decision-making process and prevent the spread of AIS by implementing risk-based prevention and mitigation management strategies. This project combined clustering detection, network analysis, and probability co-kriging to recognize dispersal patterns and estimate the risk of zebra mussel and Eurasian watermilfoil invasions while attempting to account for the reporting bias and for underreporting.
To evaluate the areas of highest risk for zebra mussel infestations, researchers looked at distance to the nearest zebra mussel infested water body, boater traffic, and road access. The Eurasian watermilfoil model was similar, looking at connectivity to infested water bodies instead of road access. Results confirmed that zebra mussel and Eurasian watermilfoil invasions are potentially confounded by human densities, which is explained by varying human impact on either or both dispersal and reporting of invasions. Considering this impact of human density, this research suggests that a combination of passive and targeted surveillance, where the magnitude of efforts are stratified by human densities, may provide insight into the true invasion status and its progression in the Great Lakes region.
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.