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Environmental Assessment

Progression of Ecological Degradation in Mid-Atlantic Streams

Objective/Intended Use

This project will develop and evaluate techniques to quantify aquatic community response along gradients of increasing stress so that the degree of relative severity of effects can be assessed and the stream reaches that may benefit most from restoration activities can be identified. Specific aquatic attributes that are lost as stress increases will be identified. We expect these results to be useful to the Regional Vulnerability Assessment (ReVA), and the Mid-Atlantic Integrated Assessment (MAIA) being conducted in the Mid Atlantic and to the Aquatic Life Uses work group in the Office of Water.

Technical Information Staff
  • by phone at:   703-347-8561
  • by fax at:   703-347-8691
  • by email at:  nceadc.comment@epa.gov

Project Abstact

This project will develop and evaluate techniques to quantify aquatic community response along gradients of increasing stress so that the degree of relative severity of effects can be assessed and the stream reaches that may benefit most from restoration activities can be identified. As anthropogenic stress increases, ecological systems degrade and important functions can be lost. Currently, the status and trends in condition of aquatic communities are most often reported dichotomously-the community is either impaired or it is similar to reference condition. A better understanding of how communities degrade as anthropogenic stresses increase will allow programs like MAIA and ReVA to better articulate the relative severity of impacts to aquatic resources.

This project will document the progression of ecological degradation in aquatic communities in the Mid-Atlantic Region and identify commonalities in the progression for different types of stress and different communities. Data sets have been compiled for the region that represent biological communities of macroinvertebrates, fish, and periphyton across the full range of stress intensities. Metrics that represent community structure have been computed for each data set. These metrics have been analyzed using multivariate statistical techniques to better understand not only how the community structure changes, but also at what points along the stressor gradient these different changes occur. Results from these analyses illustrate differences in the responses of biological metrics along gradients of anthropogenic stress. Changes in community structure have been linked to the tiered classes being developed by the Aquatic Life Uses (ALUS) work group. Analysis of changes in species lists along a gradient of anthropogenic stress will be conducted.

Project Status

A proof of concept paper was presented at the North American Benthological Society meetings, June 2001 and a journal article was also published. See products listed below.

Project Dates

Project Start Date
  09/01/2001
Project Completion Date (Actual/Projected)
  06/30/2004

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