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ASSOCIATIONS BETWEEN GENETIC DIVERSITY AND ANTHROPOGENIC DISTURBANCE IN MIDWESTERN STREAM-DWELLING MINNOWS
Bagley, M J., S E. Franson, AND S A. Christ. ASSOCIATIONS BETWEEN GENETIC DIVERSITY AND ANTHROPOGENIC DISTURBANCE IN MIDWESTERN STREAM-DWELLING MINNOWS. Presented at American Fisheries Society 2003 Annual Meeting, Quebec, Canada, August 9-15, 2003.
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.
Anthropogenic disturbances may leave imprints on patterns of intraspecific genetic diversity through their effects on population size, adaptation, migration, and mutation. We examined patterns of genetic diversity for a stream-dwelling minnow (the central stoneroller, Campostoma anomalum) in relation to several measures of environmental condition for populations residing in Ohio and Indiana, USA. Genetic differentiation among samples from 91 randomly selected first through third order streams was high. Genetic distance analyses suggested the existence of at least five major genetic lineages in this region. Average genetic diversity within sites, as measured by a similarity index, differed greatly among sites. Variables relating to stream habitat quality, geography, and contaminant exposure, were evaluated for their relationship to genetic diversity in a mixed model analysis, with stepwise elimination of least significant effects. Five effects were retained in the reduced model, which explained about half of within-site genetic diversity. Highly significant effects in the model included major genetic lineage and anthropogenic impact indicators for urbanization and riparian disturbance. Stream channelization and average stream depth at the sample site were also important. These results suggest anthropogenic disturbances can have strong influences on genetic diversity and may therefore influence the long-term sustainability of these populations.
Record Details:Record Type: DOCUMENT (PRESENTATION/ABSTRACT)
Organization:U.S. ENVIRONMENTAL PROTECTION AGENCY
OFFICE OF RESEARCH AND DEVELOPMENT
NATIONAL EXPOSURE RESEARCH LABORATORY
ECOLOGICAL EXPOSURE RESEARCH DIVISION
MOLECULAR ECOLOGY RESEARCH BRANCH