Sediment Remediation Impacts on Macroinvertebrate Community Structure: Assessing the Success of Urban Stream Restoration

摘要

Land use practices altering the natural landscape have resulted in the widespread degradation of stream ecosystems and the need for urban stream restorations. While a number of studies have evaluated the success of these stream restoration efforts, few have assessed the recovery of macroinvertebrate communities following the remediation of contaminated sediments. The purpose of my study was to evaluate the impact of sediment remediation activities on macroinvertebate abundance, diversity, and richness to determine the success of stream restoration in Ruddiman Creek, a small stream in the Muskegon Lake watershed. During my investigation, macroinvertebrate samples were collected from all available habitat types at three study sites and three reference (control) sites using a Before-After Control-Impact (BACI) sampling design. Ryerson Creek, an urban system considered less disturbed with respect to heavy metal and organic contaminants, served as a reference stream within the Muskegon Lake watershed. Physical measurements, chemical analyses of water samples, and hydrologic measurements in Ruddiman and Ryerson Creeks were used to assess habitat and water vi quality changes as a result of remediation activities. This investigation concluded that although remediation activities resulted in a significant initial decline in macroinvertebrate abundance, diversity, and richness, the macroinvertebrate community recovered to pre-remediation conditions rapidly. After approximately one and a half years of recovery, stream quality of study sites had not approached reference conditions. The family-level biotic index (FBI), however, suggested marked improvement in stream quality, as indicated by a greater abundance of sensitive taxa (%) and a richer macroinvertebrate community. My findings suggest that chronically degraded water quality and hydrologic impairments continued to negatively influence the macroinvertebrate community and that additional restoration activities are needed to improve the ecological integrity of the Ruddiman Creek watershed.