Document Type
Thesis
Date of Award
2026
Degree Name
Master of Science (MS)
Department
Biology
First Advisor
Jacob Kerby
Abstract
The spread of the invasive zebra mussel (Dreissena polymrpha) poses significant ecological and economic threats to freshwater systems across North America. Understanding population dynamics and how this aquatic invasive species spreads is essential for making natural resource management decisions. South Dakota represents an active frontline of the zebra mussel invasion, highlighting the importance of understanding the spread in this region. Statewide habitat suitability modeling of available aquatic habitat was performed using MaxEnt, a robust machine learning algorithm. Individual waterbody suitability means were also extracted to rank waterbodies within highly suitable regions. This work revealed that South Dakota possesses widespread suitable habitat, and that continued spread, driven by site-specific introduction and establishment variables is expected. To complement the broad statewide analysis, this research also investigated zebra mussel settlement on commonly occurring substrates in the Missouri River. Random stratified field sampling was conducted along the 59-mile stretch of the Missouri National Recreational River to examine zebra mussel settlement densities. This work revealed that non-natural substrates used for bank stabilization, like concrete and quartzite, are most favorable for zebra mussel settlement, and that cottonwood trees have a temporary period of promoting high zebra mussel settlement, until the tree bark is removed. Once this happens, zebra mussel density and establishment probability decrease sharply and become lower than on red cedar. Overall, this work explains zebra mussel distribution and settlement patterns in South Dakota.
Subject Categories
Biology | Ecology and Evolutionary Biology
Keywords
zebra mussel, Dreissena polymrpha, Missouri River
Number of Pages
57
Publisher
University of South Dakota
Recommended Citation
Sorensen, Justin Verner, "WHERE MUSSELS HANG OUT: A MULTISCALE ANALYSIS OF ZEBRA MUSSEL (DREISSENA POLYMORPHA) SPREAD IN SOUTH DAKOTA" (2026). Dissertations and Theses. 422.
https://red.library.usd.edu/diss-thesis/422