Impervious Surface Area and Benthic Macroinvertebrate Response as an Indicator ofImpact from Urbanization of Freshwater Wetlands

摘要

Urbanization is a continuing process in most societies around the world. Urbanland uses produce many negative outputs in the form of sediments, excess nutrients, toxicants and pathogens. These are transported as non-point source pollution into receiving wetlands by stormwater runoff draining from the surrounding landscape. Urban land practices such as construction, extraction of groundwater, draining, filling and dredging of wetlands to make way for further development, are also sources of impact. Related stresses to wetland ecosystem are either dehydration, inundation, sedimentation, light reduction, eutrophication, contamination, thermal warming, habitat fragmentation, exotic species invasion, acidification, and salinization. The evaluation of the impact to wetlands is a difficult and expensive process for management agencies. Procedures may include laboratory analysis of water and soil samples and toxicology tests. Invertebrates are becoming increasinlgy important as a measuring tool for monitoring pollution and trophic state of fresh waters. The aquatic habitat integrates most of the parameters of the environment because it accumulates water from both air and land. The presence of certain assemblages of species of aquatic invertebrates provides valuable information on water quality, as does the absence of sensitive organisms, or high populations of tolerant organisms. The use of benthic macroinvertebrates as bioindicators of water quality is not a new technique and is widely applied in streams, rivers, and lake biomonitoring programs and research.