United States Environmental Protection Agency Office of Research and Development National Exposure Research Laboratory Research Abstract Government Performance Results Act (GPRA) Goal #2 Annual Performance Measure #95 Significant Research Findings: Reduced Diversity of Benthic Macroinvertebrates in the Willimantic River, Connecticut: a causal analysis illustrating iterative investigation and adaptive management. The Clean Water Act (CWA) requires that states adopt water quality standards that support designated uses including aquatic life use. States and tribes often measure a waterbody's ability to support aquatic life by sampling fish, invertebrates, and plants. If the measurements that are based on biological entities deviate from expected norms, then the waterbody may be listed under the CWA as impaired. If a waterbody is listed as impaired, Section 303(d) of the CWA requires states and tribes to determine the cause of the biological impairment, to calculate a level of the pollutant that may occur while allowing the biological condition to return to acceptable levels, and to prepare an implementation plan to achieve these objectives. Determining the cause of a biological impairment can be a daunting task, one that is complicated by multiple possible causes, spotty or irregularly collected data, natural variations due to season, weather, land formation and other factors, and lack of the basic scientific information needed to diagnose environmental problems. Nevertheless, the probable causes of biological impairments can be determined and the findings can be used to reduce or remove detrimental causes and improve the condition of biological communities. This report illustrates a case in which a cause was determined, corrected, and the biological diversity of a stream increased. Research This report illustrates a case in which a cause was determined, corrected, and the Approach biological diversity of a stream increased. An initial analysis was followed by a second causal analysis which identified probable causes of impairment associated with similar sources scattered throughout a watershed. Both causal analyses used a formal process for organizing and analyzing evidence as described in the Stressor Identification Guidance Document (EPA/822/B-00/025) and other EPA documents. Scientific Problem and Policy Issues Results and To assist resource managers in determining the causes of biological Impact impairment, this case study provided an opportunity to discover some of the potential modifications, clarifications and additional tools that could help ------- make causal analysis more rigorous, consistent and transparent. This case study illustrates several effective tools used to determine causes of biological impairment including: • ~ Preliminary analysis leading to the collection of additional information. • D Using screening level methods to bracket a biological impairment and its sources. • D Using temporal data to eliminate some causal pathways and to strengthen others. • D Using adaptive management to take steps to confirm one cause and reveal others. • D Comparing and evaluating multiple probable causes. • D Analyzing evidence for individual stream segments and a group of sites which have similarly modified invertebrate assemblages. This case study is an example of adaptive management. Adaptive management is the practice of using models or logic to suggest an appropriate management action, carrying out that action experimentally, monitoring the results of the action, and using the results of monitoring to modify the model or logic and recommend modified or additional actions. This iterative and adaptive approach can efficiently bring about and document improvements in the quality of impaired ecosystems and was demonstrated in this study where adaptive management improved stream condition. This research helped meet LONG TERM GOAL 2: Provide the tools to assess and diagnose sources and causes of impairment in aquatic systems; the 2008 APG: Equip EPA Regions, States and Tribes with knowledge, skills and tools to determine the causes of impairments for freshwater and coastal systems required in various regulations; and the 2003 APM #95: Case study demonstrating the Stressor Identification Process that identifies the causes of biological impairment in the nation's waterbodies. Research Collaboration and Research Products Publications are being developed. Primary Authors: EPA. Office of Research and Development: Susan M. Cormier, Connecticut Department of Environmental Protection: Christopher Bellucci; Guy Hoffman Contributing Authors: EPA. Office of Research and Development: Glenn W. Suter II, Ph.D.: Susan Braen Norton, Ph.D.; Bhagya Subramanian; Brad Autrey; Participants at the 30th Annual Biological Advisory Committee Meeting Participants, May 9-11, 2000 Office of Research and Development: Randall J.F. Bruins, NCEA; Gary Collins, NCEA; Susan Cormier, NERL; Chris Cubbison, NCEA; Joe Flotemersch, NERL; Terry Flum, NERL; Florence Fulk, NERL; Robert Graves, NERL; Sally Guiterrez, NRMRL; Fran Kremer NRMRL; Jim Lazorchak, NERL; Michael Lewis, NHEERL; Suzanne Lussier, NHEERL; Teresa Norberg-King, NHEERL; Bhagya Subramanian, NERL; Glenn Suter II, NCEA; Michael Troyer, OSP; Naiming Wang, NERL; Kevin Wehrly, NERL; Sue Norton, NCEA U.S. EPA Regional Offices: Peter Nolan, Region 1; James Kurtenbach, Region 2; Maggie Passmore, Region 3; Anne Keller, Region 4; Charles Steiner, Walter L. Redmon, Peg Donnelly, Ed ------- Hammer, Region 5; Abel Euresti, Philip Crocker, Region 6; Gary Welker, Region 7; Loys Parrish, Region 8; William Schroeder, Region 8; Peter Husby, Region 9 U. S. EPA Program Offices: Kathryn Gallagher, Office of Water; D. Scott Ireland, Office of Water; Michael Kravitz, OERR; Donna Reed-.Tudkins, Office of Water; Jerry Smrchek, OERR; Evangeline Tsibris, Office of Environmental Information Connecticut Department of Environmental Protection: Chris Bellucci and Guy Hoffman, Peer Reviewers: Frank Borsuk, Ph.D., Region III, USEPA, Wheeling, WV Jeroen Gerritsen, Tetra Tech, Inc., Owing Mills, MD Ernest Pizzuto, Connecticut Department of Environmental Protection, Hartford, CT Leela Rao, NCEA, ORD, USEPA Washington DC The authors would like to recognize others who helped to prepare this document including Richard N. Racine, Ph.D., Alicia Sheoton, Eric O'Neal, Katherine Loizos and Melda Hirth. Future Research Two other case studies currently under investigation, the Groundhouse River in Minnesota and Long Creek in Maine, are expected to yield additional ways for states to collect and use their monitoring data to develop lines of evidence for identifying probable causes of biological impairment. Contacts for Questions and inquiries can be directed to: Additional Susan M. Cormier, Ph.D. Information US EPA National Exposure Research Laboratory Cincinnati, OH 45268 Phone:513-569-7995 E-mail: cormier.susan@epamail.epa.gov ------- |