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GENETIC DIVERSITY OF STREAM FISH IN THE MID-ATLANTIC INTEGRATED ASSESSMENT AREA
Citation:
Bagley, M J., S A. Jackson, S E. Franson, AND E R. Waits. GENETIC DIVERSITY OF STREAM FISH IN THE MID-ATLANTIC INTEGRATED ASSESSMENT AREA. U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-04/175 (NTIS PB2006-114613), 2004.
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:
In this report, we describe the results of research to assess the genetics of three stream fish species in the Mid-Atlantic region. This research had three specific goals. First, we sought to examine the utility of genetic analysis for purposes of taxonomic identification. Bioassessments depend critically on accurate taxonomic identification, yet for many species morphological identification is problematic and prone to error. The use of "DNA taxonomy" may provide an effective solution to improve the accuracy, consistency, and precision of taxonomic identification. Second, we sought to understand the population structure of the three target species within the Mid-Atlantic region. Most species are divided into population segments that may be partially or completely reproductively isolated. These populations represent the fundamental resource units for these species, and therefore are important to delineate when performing ecological assessments. If the population boundaries are similar for different species, then precise biogeographic provinces could be identified using this methodology. Finally, we sought to determine the relationship between measurements of genetic diversity for these three stream fish and stressor profiles previously generated for the Mid-Atlantic region. If a genetic signature of stressors can be detected based on their cumulative impacts on populations, measurements of genetic diversity may provide an effective leading indicator of population level impacts prior to population extirpations.