Use of GIS to Determine Potential Sources of Aquatic Invasive Species Invasions into Western South Dakota Reservoirs

Abstract

The spread of Aquatic Invasive Species (AIS) is a constant threat for western US waters. The state of South Dakota detected zebra mussels ( Dreissena polymorpha ) for the first time at Lewis and Clark Reservoir in 2014. Since then, efforts have been towards preventing their further expansion. To determine possible avenues of infestation westward, we used ArcGIS to map the home zip codes of boaters using four western reservoirs (Belle Fourche Reservoir, Pactola Reservoir, Sheridan Lake and Angostura Reservoir). A 60-mile buffer was used to determine spatial relationships of boater zip codes to establish zebra mussel populations and was considered areas of high risk. We found that there were three instances where a boater came from a high-risk area during the study period. Our results show possible pathways for Dreissena expansion into western South Dakota reservoirs. Most notably is that exposure can occur from either an inter- or intra-state vector. This information confirmed that there is a risk of additional water bodies in South Dakota becoming infected. Based on past studies, prevention is the best method in slowing the expansion of zebra mussels in South Dakota. We suggest three actions, strategically placed decontamination stations, continued public awareness efforts and differentiating boat registration tags on watercraft that are near infested water bodies.