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      A multi agency project funded by US EPA's STAR Program
 

Great Lakes Diatom and Water Quality Indicators
(Abstract PDF)

Investigators and Institutions:
Principal Investigators: John C. Kingston, PhD, Natural Resources Research Institute (NRRI) Ely, MN, University of Minnesota Duluth; Richard Axler, PhD, NRRI, University of Minnesota Duluth; Euan Reavie, PhD, NRRI Ely, University of Minnesota Duluth
Co-Principal Investigators: Eugene F. Stoermer, PhD, CGLAS; SNRE, University of Michigan, Ann Arbor; Jeffrey R. Johansen, PhD, and Gerald V. Sgro, PhD, Biology, John Carroll University, Ohio
US EPA Office of Research and Development Cooperators: Russell G. Kreis, Jr., PhD, Grosse Ile, MI; Jo Thompson, MS, MED, Duluth, Minnesota

Project Summary

Objectives:
Quantify the extent to which pressure indicators influence diatom community structure in nearshore wetlands, estuaries, and reaches of the Laurentian Great Lakes:
a. Develop predictive models through multivariate analyses of communities and ecosystems to:
i) infer ecological status at local and regional scales, and
ii) describe pre-disturbance-to-recent baselines, trends, and magnitudes of change in restricted river-influenced and other wetlands;
b. Evaluate and modify existing diatom metrics, and devise and validate new diatom metrics, so that a number of state indicators for nutrient loading, siltation, and salinity in nearshore waters of the Great Lakes will be available to federal and state agencies;
c. Construct multimetric diatom indices from the best of these state or condition metrics;
d. Develop integrated indices of biotic integrity based on a combination of selected metrics developed in the diatom subprogram and by other teams in the larger program; and
e. Develop a QA/QC infrastructure for the diatom subprogram and future assessment efforts.

Experimental Approach:
The utility of diatom "state" indicators in evaluating stressors in aquatic ecosystems is well recognized by US EPA and other agencies. Diatom species respond with great fidelity to stressors associated with major "pressure" indicators in the Great Lakes - nutrient and salinity loading, siltation, and factors affecting water transparency including exotic species. We take a comprehensive approach to developing indicators (MVA, metrics, and indices) for near-coastal ecosystems. We use proven methods for indicators suitable for the entire Great Lakes basin. Retrospective assessment using short sediment cores gives us measures of reference condition. Integration with other program components will allow development of indices of biotic integrity (integrated condition) of near-coastal ecosystems. The diatom indices will provide "ground truth" for aquatic responses of landscape measures that are developed in the omnibus proposal.

Expected Results:
The research will develop and evaluate indicators by local habitat, by lake, by ecoregion, and by stressor activity/intensity. The diatom project will provide linkages from ecosystem function to water quality and to pressure indicators documented by other subproposals. We are confident that a suite of powerful diatom indicators can be developed for key pressure indicators for use throughout the Great Lakes basin.