You are here:
REGION-WIDE GENETIC STRUCTURE OF THE CENTRAL STONEROLLER (CAMPOSTOMA ANOMALUM) AND THE RELATIONSHIP OF GENETIC DIVERSITY TO ENVIRONMENTAL QUALITY
Citation:
Franson, S E., M J. Bagley, S A. Christ, T K. Wessendarp, G P. Toth, AND M K. Smith. REGION-WIDE GENETIC STRUCTURE OF THE CENTRAL STONEROLLER (CAMPOSTOMA ANOMALUM) AND THE RELATIONSHIP OF GENETIC DIVERSITY TO ENVIRONMENTAL QUALITY. Presented at Society of Enviornmental Toxicology and Chemistry, Nashville, TN, November 12-16, 2000.
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:
Anthropogenic stressors that reduce population size, alter migration corridors or modify mutational and selective forces on populations are expected to leave a lasting genetic footprint on the distribution of intraspecific genetic variation. Thus, the pattern of intraspecific genetic variation within and among populaitons should be a natural indicator of the condition of populations and the environments in which they are found. To the extent that extinction risk is determined by genetic variability, the pattern of genetic variation is also a useful indicator of population vulnerability. As a first step in gauging the usefulness of genetic diversity as an ecological indicator, we assessed the regional genetic structure of the cyprinid fish Campostoma anomatum (central stoneroller) in streams throughout the Eastern Cornbelt Plains Ecoregion. Patterns of genetic variation within and among populations were examined for samples collected from 110 sites using the random amplified polymorphic DNA (RAPD) technique. Sampling was done in conjunction with USEPA's Regional Environmental Monitoring and Assessment Program (REMAP), which provided simultaneous data for environmental variables that could be correlated to the genetic data. Analyses using Lynch's Similarity Index revealed that populations within the ecoregion were highly differentiated, indicating that gene flow between sites was generally low. Preliminary assessments of correlative environmental data suggest that genetic diversity of individuals within populations is positively correlated to both habitat quality (Qualitative Habitat Evaluation Index) and community structure (Index of Biotic Integrity). These preliminary resutls suggest that differences in genetic diversity among populations, when viewed in a regional context, are highly informative indicators of ecological condition and relative vulnerability of populations.