¹Central Michigan University, Department of Biology, Brooks 156, Mount Pleasant, MI 48859
²Michigan State University, Departments of Zoology and Fisheries and Wildlife 25B Natural Science, East Lansing, MI 48824
³Michigan State University Department of Zoology, 25B Natural Science, East Lansing, MI 48824
⁴Grand Valley State University, Annis Water Resources Institute, 740 W. Shoreline Dr. Muskegon, MI 49441

*Corresponding author: uzars1dg@cmich.edu

Abstract

   Many Great Lakes coastal wetlands that remain today have been heavily fragmented by anthropogenic activities. The rate of fragmentation tends to increase during periods of low lake levels, especially in areas of low-gradient bathymetry where wetland area expands substantially and prompts the desire to dredge channels and groom shorelines. We sampled fish and invertebrates, using fyke nets and dipnets respectively, from wetland fragments paired with either area where wetland vegetation was mowed or removed completely. Our concurrent studies showed that removal of vegetation by beach grooming and channel dredging created conduits for pelagic water to infiltrate the marsh and disrupt the ambient chemical/physical conditions. Alterations to both fish and macroinvertebrate communities were also evident where a significant amount of vegetation was removed. However, where only enough vegetation was removed to allow for boat access, impacts on fish communities were generally non-detectable. Mowing seemed to impact fish, but not invertebrates. Our data suggest that wetland fragmentation may have substantial and long lasting effects on wetland biota, but the magnitude of the impact is likely associated with the area of vegetation removed coupled with the potential for pelagic water to penetrate remaining fragments.