Zebra Mussels in the Neosho River Basin: Ecology and Economics

Abstract

The zebra mussel (Dreissena polymorpha) is an invasive freshwater mollusk introduced to North America in 1987. Since that time, its range has rapidly spread south and west across the United States, and its current contiguous range extends to Kansas. Kansas waterways are, therefore, on the forefront of this expansion, and a better understanding of the effects of this invasive species in Kansas waters will aid in the preparation for zebra mussel range expansion. With a goal of gaining a better understanding of the ongoing issues of this invasion into a newly-infested river basin, my research addressed two topics: 1. ecology of zebra mussel dispersal in the Neosho River Basin; and 2. economic implications of this infestation. The ecological aspect of my research consisted of monthly sampling of larval and adult zebra mussel populations from March to November 2011 at sites in the Upper Neosho River Basin in Kansas, as well as examining zebra mussels’ utilization of various materials (PVC, concrete, steel, galvanized steel, pressure-treated wood, aluminum, and unionid shell) and effectiveness of the Intersleek® 970 Fluoropolymer foul release coating system. Zebra mussels showed differential colonization of reservoir reaches, with the greatest densities found closest to the reservoir dam. Following discharge from these reservoirs, zebra mussel numbers declined drastically. In downstream rivers, zebra mussel population spikes occurred in waters impounded by lowhead dams. Lastly, zebra mussels differentially colonized various materials, and the foul release coating system reduced their ability to colonize substrates. Assessment of the economic impacts of zebra mussels was conducted via a mailer survey sent to water rights holders in the Neosho and Walnut river basins. I estimate that the annual cost of zebra mussels in 2011 was $374,206 in the Neosho and $11,600 in the smaller Walnut.