THURSDAY, MARCH 2, 2006

Topic: Long term biological monitoring of the Penobscot River as illustrated with a field-based stressor-response model, the Biological Condition Gradient

Author: Susan P. Davies, Maine Department of Environmental Protection, SHS 17, Augusta, ME 04333

Standardized benthic macroinvertebrate monitoring by the Department of Environmental Protection, in partnership with the University of Maine and the Penobscot Indian Nation (PIN) has been occurring on the Penobscot River mainstem since the early 1970s. This long record spans a period of dramatic improvements in wastewater treatment, with consequent dramatic improvements in the condition of aquatic life. The State of Maine has been well-positioned to document and preserve the improvements in biological condition in the Penobscot River because of the close relationship that exists between the state biomonitoring program and state water quality management laws. The laws set standards for the condition of aquatic life and are termed tiered aquatic life uses (TALU). The tight linkage between monitoring and water quality standards provides a scientifically and legally sound context to apply principles of ecological risk assessment (ERA) and ecological restoration. ERA focuses on the cause:effect relationship between stressors and observed responses in ecological condition and ecological restoration represents the human actions to ensure that degraded systems are returned to a state of structural and functional integrity. Biological monitoring and criteria play crucial roles in both of these disciplines, the former by documenting the biological response to stressors and the latter, by establishing quantitative goals for resource condition. Adoption of tiered standards for biological condition help to inform and mobilize society to make incremental progress toward the explicit ecological goals required in both ecological risk assessment and ecosystem restoration. These concepts will be illustrated using a field-based stressor-response model termed the Biological Condition Gradient. A national workgroup sponsored by the US Environmental Protection Agency developed the model based on the experience of biological criteria programs in Maine and Ohio.

Speaker: Susan Davies, Biomonitoring Unit, Maine Dept. of Environmental Protection

Susan Davies has a bachelor’s degree from Columbia University and a master’s degree in aquatic entomology from the University of Maine. Between 1983 and 2003 she was manager of the Maine DEP Biological Monitoring Program and is now water quality standards coordinator for the Department. In 1997-1998 she was invited to work with the EPA National Biocriteria Program in Washington, D.C. on large river bioassessment and national biocriteria implementation issues. Between 1998 and 2003 she and Susan Jackson of the EPA National Biocriteria Program co-chaired the EPA Tiered Aquatic Life Uses (TALU) National Workgroup that developed the Biological Condition Gradient model. In 2003, Susan, David Courtemanch and Leon Tsomides, from the MDEP Biomonitoring Program were recognized with an Environmental Merit Award for Lifetime Achievement from Region 1 EPA, in recognition of the State of Maine’s innovative and effective use of biological information in water quality management.