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UNDERSTANDING THE RELATIONSHIPS AMONG WATERSHEDS, STREAMS, AND RECEIVING COASTAL ECOSYSTEM
Citation:
Lussier, S M. AND C Wigand. UNDERSTANDING THE RELATIONSHIPS AMONG WATERSHEDS, STREAMS, AND RECEIVING COASTAL ECOSYSTEM. Presented at Watersheds 2002, Fort Lauderdale, FL, February 23-27, 2002.
Description:
The U.S. Environmental Protection Agency has developed the biocriteria program to incorporate biological indicators as part of state water-quality standards. Biological data have been collected for many years for different components of watersheds and contribute valuable information on the ability of surface waters to sustain aquatic life. Indices of biotic integrity are routinely used to measure the condition of both fresh and salt water bodies as distinct ecosystems. Because watersheds provide pathways for point and non-point stressors to affect receiving ecosystems, we saw a need to integrate indicators of condition of the watershed with those of its receiving salt marsh. Differences in land use throughout the watershed (sources and sinks) affect how local biotic communities respond to effects from stressors such as nutrient enrichment and, consequently, may change the structure and function of the aquatic ecosystems. Assessment of the stream communities may provide information about nutrient loading to the salt marsh and help us understand the relationship among upstream watershed attributes, conditions in streams, and conditions in salt marshes. Our approach evaluates data from these watershed components by comparing diagnostics of streams with those of their receiving coastal ecosystems. The specific objective of this study is to examine assessment data from benthic invertebrate communities in streams and test their correlations with indicators of salt marsh condition. In this study, we analyze biological assessment data from six. Rhode Island watersheds selected along an anthropogenic gradient based on percent residential land use and estimated diffuse nitrogen loadings, and compare them with the condition of their receiving coastal salt marshes. Using the Rapid Bioassessment Protocol (RBP), we collect biological, chemical, and physical habitat data from six stream reaches (including a reference site) and compare metrics of structure and integrity of the streams with similar metrics of the receiving salt marshes. Data analysis will show how well indicators of stream condition correlate with those of receiving coastal marshes along an anthropogenic land use gradient. Our research should have implications for the management of non-point source pollutants such as nitrogen.