Document Type
Thesis - Open Access
Award Date
2025
Degree Name
Master of Science (MS)
Department / School
Natural Resource Management
First Advisor
David Coulter
Abstract
Invasive species disrupt ecosystems by altering habitats, competing with native species, and disrupting food webs. The northern Great Plains is an ecologically important region with many wetlands, lakes, and rivers that are under threat from two invasive species, Bighead (Hypophthalmichthys nobilis) and Silver Carp (H. molitrix; bigheaded carp). These large planktivores change the abundance and composition of phytoplankton and zooplankton communities which alters prey for native mussels, fishes, and, potentially, waterfowl. Bigheaded carps have invaded a portion of the Northern Great Plains, and preventing further spread is a primary management goal. My work assists these efforts by providing tools to improve preventative management actions for bigheaded carp. While prevention is critical, monitoring all waterbodies for early introductions is impractical. My second chapter aims to help managers prioritize surveillance monitoring locations by predicting habitat suitability for bigheaded carp across 53 waterbodies (wetlands, lakes, and rivers) in the region. I used an individual-based model that predicted bigheaded carp survival and growth based on observed environmental conditions. These predictions helped categorize waterbodies from very high to low risk, guiding managers in prioritizing surveillance efforts and ensuring efficient use of resources. Once high-risk locations are identified, managers still need to know where within a waterbody to sample because invasive individuals are often rare and patchy in occurrence. Since individuals commonly seek patches of high-quality habitat, my third chapter used a modeling approach to predict growth rate potential as a fine-scale habitat quality metric. I then assessed the extent to which the location of high-quality habitat changed throughout the year and assessed whether this occurred more in certain habitat types. The location of high-quality habitat patches was consistent through time for wetlands and lakes, whereas these locations were quite variable throughout the year in rivers. These results suggest that it might be beneficial for sampling protocols to be customized for particular habitat types. Overall, these results will assist management efforts to contain bigheaded carp populations by providing data-driven information about habitat suitability that can be used to target management efforts to the most at-risk locations and to efficiently use management resources.
Publisher
South Dakota State University
Recommended Citation
Elwer, Brenden M., "Integrating Invasion Risk and Habitat Suitability to Guide Invasive Species Management in Wetlands, Lakes, And Rivers" (2025). Electronic Theses and Dissertations. 1527.
https://openprairie.sdstate.edu/etd2/1527
Rights Statement
