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Landscape Genetics of the Great and Little Miami Watersheds
Objective:
- Assess relationships between genetic diversity and landscape features relative to ecological condition and population viability across a suite of freshwater fish species
- Define biologically meaningful sampling units for ecological assessments
Approach:
- Community genetic analyses of fish species' (central stonerollers, creek chubs, fantail darters, orangethroat darters, and rainbow darters) population structure and stability
- Remote sensing analyses of land cover and land use in the Great and Little Miami basins
- Tissue analysis to determine exposure of fish species to pesticides and PCB analytes
- Parameterization of metapopulation models from genetic and landscape data
Why This Research Is Needed:
The US EPA is pursuing research into new and sophisticated indicators of ecological condition for aquatic resources. These indicators are needed as the agency increasingly shifts from assessments of potent, highly localized pollutants to assessment of more widespread, non-point source environmental factors. This demonstration project seeks to evaluate the synergisms between different ecological indicators, to resolve uncertainties about the linkages between them, and to determine whether future ecological assessments will be improved by utilizing integrative approaches. In particular, this study will assess the condition of stream fish populations in the Great Miami and Little Miami watersheds of southwestern Ohio and eastern Indiana. Specifically, we will evaluate the structure of fish populations and putative causative factors that are associated with changes in population structure. Through an approach that integrates landscape, genetic, and population modeling information, we seek to answer the following questions:
- To what extent does stream size and connectivity structure fish populations in the Great Miami and Little Miami watersheds?
- Do stream channel alterations and changes in impervious surfaces correlate with changes in fish population structure?
- Do nutrient loadings correlate with changes in fish population structure?
- Does the level of pesticide exposure correlate with changes in fish population structure?
- Are changes in population structure correlated with changes in biological integrity?
Expected Outputs/Outcomes:
- Development of an integrated assessment approach utilizing genetic, landscape ecology and population modeling tools which can be used by risk assessors
- A demonstration of how integrative assessment methods which can provide robust measures of exposure to non-point source pollution
Partners:
- US EPA, NERL-Las Vegas; US EPA, NERL-Athens
Contact: Mark Bagley bagley.mark@epa.gov, Mike Blum blum.mike@epa.gov (Cincinnati, OH)