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GENETIC DIVERSITY AS AN INDICATOR OF ECOSYSTEM CONDITION AND SUSTAINABILITY: UTILITY FOR REGIONAL ASSESSMENTS OF STREAM CONDITION IN THE EASTERN UNITED STATES
Citation:
Bagley, M J., S E. Franson, S A. Christ, E R. Waits, AND G P. Toth. GENETIC DIVERSITY AS AN INDICATOR OF ECOSYSTEM CONDITION AND SUSTAINABILITY: UTILITY FOR REGIONAL ASSESSMENTS OF STREAM CONDITION IN THE EASTERN UNITED STATES. U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-03/056 (NTIS PB2004107063), 2003.
Impact/Purpose:
The objective of this task is to develop molecular indicators to evaluate the integrity and sustainability of aquatic fish, invertebrate, and plant communities (GPRA goal 4.5.2). Specifically, this subtask aims to evaluate methods for the measurement of:
fish and invertebrate community composition, especially for morphologically indistinct (cryptic) species
population genetic structure of aquatic indicator species and its relationship to landscape determinants of population structure (to aid in defining natural assessment units and to allow correlation of population substructure with regional stressor coverages)
genetic diversity within populations of aquatic indicator species, as an indicator of vulnerability to further exposure and as an indicator of cumulative exposure
patterns of temporal change in genetic diversity of aquatic indicator species, as a monitoring tool for establishing long-term population trends.
Description:
This report documents research undertaken to determine if the theoretical promise of genetic diversity as an ecological indicator is realized in real-world applications. Results of two case studies confirm that genetic diversity is a useful indicator of environmental condition. The first case study incorporated the genetic diversity indicator in a larger Regional Environmental Monitoring and Assessment Program study of the Eastern Cornbelt Plains Ecoregion, done in collaboration with USEPA Region 5 and Ohio EPA. Genetic diversity of a small cyprinid minnow, the central stoneroller (Campostoma anomalum) was measured at 91 sites in nine watersheds using the RAPD (random amplified polymorphic DNA) fingerprinting technique. The second case study examined the genetic diviersity indicator applied to populations of the creek chub (Semotilus atromaculatus) in a small region of western Pennsylvania and West Virginia underlain by coal-bearing geology and for which the history of coal mining operations is known. Samples of between 9 and 28 creek chubs were collected from 10 sites within 4 watersheds. Two molecular methods were used: the amplified fragment length polymorphism (AFLP) fingerprinting technique was used to assess diversity in the nuclear genome, while a portion of the mitochondrial genome was assessed using DNA sequencing. These two case studies clearly demonstrate that genetic diversity can serve as an indicator of environmental condition. They also provided the practical experience upon which recommendations for future implementation are based.