Tessa Julianne Code
Karl D. Stenberg
Jonathan H Mclean
Benjamin Lorenz Jensen
Marshal S. Hoy
David Beauchamp
Rachelle Carina Johnson
2024
<p><span>Aquatic invasive species can affect food web structure, native fish growth, and production, depending on the traits of the invasive species and the pre-invasion conditions of the ecosystem. Thermal tolerances and behavioral traits can further influence differential exploitation of resources shared between native and invasive species. An unauthorized introduction of redside shiner (</span><i>Richardsonius balteatus</i><span>) into reservoirs in the Upper Skagit River, Washington, USA caused concern of potential competition, decreased production, and recruitment of rainbow trout (</span><i>Oncorhynchus mykiss</i><span>). We combined bioenergetics modeling and stable isotope analysis with field data to quantify consumption demand of native and invasive fishes and related consumption to the availability of key zooplankton prey. Per capita consumption on </span><i>Daphnia</i><span> by redside shiner was low; however, their high abundance imposed considerable demand on prey resources in Ross Lake. Although monthly consumption demand by the fish community was less than 50% of the monthly production and biomass of </span><i>Daphnia</i><span> in Ross Lake, the current </span><i>Daphnia</i><span> densities and growth of rainbow trout were considerably lower than before the invasion. These reductions correspond to lower annual consumption of </span><i>Daphnia</i><span>. Our study provides insight on mechanisms that influence food web impacts of an invasive omnivore in cold-water reservoirs.</span></p>
application/pdf
10.1007/s10750-024-05540-3
en
Springer
Change in growth and prey utilization for a native salmonid following invasion by an omnivorous minnow in an oligotrophic reservoir
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