Date Approved


Graduate Degree Type


Degree Name

Biology (M.S.)

Degree Program



The first objective of this study was to determine the relationship between zebra mussel densities/biomass and benthic macroinvertebrate composition and density in the Muskegon River at a site near Croton Dam, Thirteen benthic quadrat samples were taken along a range of zebra mussel and macroinvertebrate densities at a single sample location. Turbellaria was the only taxa to have a significant positive relationship with zebra mussel density and biomass, Simuliidae had a positive, non-significant relationship with both. No macroinvertebrate taxa decreased because of zebra mussel density/biomasss. The other objectives of this study were to compare current macroinvertebrate communities in the Muskegon River and Bigelow Creek, as well as between the1998 and 2011 samples. Benthic samples were taken at six sites (in summer and fall) in a 22.5 km reach downstream of Croton Dam of the Muskegon River, and two sites on Bigelow Creek, using Hess samples and five-rock clusters. Macroinvertebrate community richness, EPT richness, Shannon-Wiener diversity, and evenness were calculated for each site, as well as zebra mussel densities. Macroinvertebrate and zebra mussel densities were highest in the upper sample sites on the Muskegon River. Macroinvertebrate production shifted from the mid-river sites in 1998 to the upper sites near Croton Dam in 2011 on the Muskegon River. Cheumatopsyche increases in the Muskegon River were the driving taxa in community changes from 1998 to 2011. Bigelow Creek also experienced changes between the 1998 and 2011 samples, primarily due to a shift in taxa from Protoptila and Hydropsychidae to Baetidae and Simuliidae. A single factor could not be found for the cause in the change in macroinvertebrate communities from 1998 to 2011 with the data studied, but is likely due to the invasion of zebra mussels in the Muskegon River as well as environmental changes in both Bigelow Creek and Muskegon River.

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Biology Commons