Effects of Zebra Mussel Invasion on Juvenile Steelhead Distribution, Diet, Growth, and Condition in the Muskegon River, Michigan

YOY Steelhead;Zebra Mussel;Diet;Muskegon River;Natural Resources and Environment

Giuliano, AngelaDiana, James ;

University of Michigan

关键词: YOY Steelhead;    Zebra Mussel;    Diet;    Muskegon River;    Natural Resources and Environment;   

Others  :  https://deepblue.lib.umich.edu/bitstream/handle/2027.42/86063/Giuliano_M.S.Thesis_Final.pdf?sequence=1&isAllowed=y

瑞士|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

Dreissenid mussels (zebra mussels Dreissena polymorpha; quagga mussel,D. bugensis) are an invasive species from the Ponto-Caspian region. Since theirintroduction, zebra mussels have drastically changed Great Lakes aquaticecosystems by altering nutrient cycling, biomass and species composition oflower trophic levels, with consequent impacts on fish community composition,diet and growth. This study examined zebra mussels’ effects on the spatialdistribution, diet and growth of age-0 steelhead (Oncorhynchus mykiss) in theMuskegon River, a major tributary of Lake Michigan. Densities, spatialdistributions, diets, sizes and growth rates of age-0 steelhead were compared from1998, before zebra mussel invasion, to the 2000-2003 period, post zebra musselinvasion. Before zebra mussel introduction, the majority of age-0 steelhead werefound in the upper portion of the study reach in strata 1 and 2. After zebra musselintroduction, age-0 steelhead were found in strata 2 and 5 in the summer andstratum 2 in the fall. Following zebra mussel introduction, mean weights, lengths,condition and growth rates of age-0 steelhead decreased. Significant changes inthe diet were observed in the pre- and post-zebra mussel periods (χ2=21.05,p=0.007). While age-0 steelhead consumed mostly Amphipoda (42%) andTrichoptera (27%) in 1998 before zebra mussel invasion, decreases in theabundance and availability of Trichoptera resulted in a post-zebra mussel dietshift to Diptera (51%) and Amphipoda (30%). Using bioenergetics modeling, itwas determined that the change in growth of age-0 steelhead was mainly causedby the changes in diet following the introduction of zebra mussels, rather thandifferences in water temperature over the study period. Reduced growth of age-0steelhead has negative implications for steelhead survival and potentialrecruitment if survival is size-dependent.