Bioindicators for Assessing Ecological Integrity of Prairie Wetlands

Report # EPA/ 600/ R-96/ 082
September 1995

by Paul R. Adamus*

Table of Contents:

Preferred citation
Acknowledgments

1. Introduction

1.1 Need for This Document
1.2 Document Organization
1.3 Cumulative Effects of Stressors
1.4 Glossary, Abbreviations, and Place Names
1.5 Statistical Analyses: Objectives and Methods

2. Algae and Microbial Communities as Indicators of Prairie Wetland Integrity

2.1 Ecological Significance and Suitability as an Indicator
2.2 Potential Indicator Metrics
2.3 Previous and Ongoing Monitoring in the Region
2.4 Response to Stressors

2.4.1 Algae and Microbial Communities as Indicators of Hydrologic Stressors
2.4.2 Algae and Microbial Communities as Indicators of Vegetative Cover Condition
2.4.3 Algae and Microbial Communities as Indicators of Wetland Salinity
2.4.4 Algae and Microbial Communities as Indicators of Sedimentation and Turbidity
2.4.5 Algae and Microbial Communities as Indicators of Excessive Nutrient Loads and Anoxia
2.4.6 Algae and Microbial Communities as Indicators of Pesticide and Heavy Metal Contamination

2.5 Monitoring Techniques

2.5.1 Direct Sampling
2.5.2 Indirect Sampling Through Measurement of Processes
2.5.3 Analysis of Historical Conditions
2.5.4 Bioassay Methods

2.6 Variability and Reference Points

2.6.1 Spatial Variability
2.6.2 Temporal Variability

2.7 Collection of Ancillary Data
2.8 Sampling Design and Required Level of Sampling Effort
2.9 Summary

3. Vascular Plants as Indicators of Prairie Wetland Integrity

3.1 Ecological Significance and Suitability as an Indicator
3.2 Potential Indicator Metrics
3.3 Previous and Ongoing Monitoring in the Region
3.4 Response to Stressors

3.4.1 Vascular Plants as Indicators of Hydrologic Stressors
3.4.2 Vascular Plants as Indicators of Vegetative Cover Condition
3.4.3 Vascular Plants as Indicators of Wetland Salinity
3.4.4 Vascular Plants as Indicators of Sedimentation and Turbidity
3.4.5 Vascular Plants as Indicators of Excessive Nutrient Loads and Anoxia
3.4.6 Vascular Plants as Indicators of Pesticide and Heavy Metal Contamination

3.5 Monitoring Techniques

3.5.1 Ground-based Sampling
3.5.2 Aerial Methods
3.5.3 Potential or Historical Vegetation
3.5.4 Bioassay Methods
3.5.5 Bioaccumulation

3.6 Variability and Reference Points

3.6.1 Spatial Variability
3.6.2 Temporal Variability

3.7 Collection of Ancillary Data

3.8 Sampling Design and Required Level of Sampling Effort

3.8.1 General Considerations
3.8.2 Asymptotic Richness
3.8.3 Power of Detection

3.9 Summary

4. Invertebrates as Indicators of Prairie Wetland Integrity

4.1 Ecological Significance and Suitability as an Indicator
4.2 Potential Indicator Metrics
4.3 Previous and Ongoing Monitoring in the Region
4.4 Response to Stressors

4.4.1 Invertebrates as Indicators of Hydrologic Factors
4.4.2 Invertebrates as Indicators of Changes in Vegetative Cover
4.4.3 Invertebrates as Indicators of Wetland Salinity
4.4.4 Invertebrates as Indicators of Sedimentation and Turbidity
4.4.5 Invertebrates as Indicators of Excessive Nutrient Loads and Anoxia
4.4.6 Invertebrates as Indicators of Pesticide and Heavy Metal

4.5 Monitoring Techniques

4.5.1 General Considerations
4.5.2 Sampling Equipment
4.5.3 Time-Integrating Methods
4.5.4 Bioassay Methods
4.5.5 Bioaccumulation

4.6 Variability and Reference Points

4.6.1 Spatial Variability
4.6.2 Temporal Variability
4.6.3 Spatial vs. Temporal Variability

4.7 Collection of Ancillary Data
4.8 Sampling Design and Required Level of Sampling Effort

4.8.1 General Considerations
4.8.2 Asymptotic Richness: Results of Analysis
4.8.3 Power of Detection: Results of Analysis

4.9 Summary

5. Amphibians as Indicators of Prairie Wetland Integrity

5.1 Ecological Significance
5.2 Potential Indicator Metrics
5.3 Previous and Ongoing Monitoring
5.4 Response to Stressors
5.5 Variability and Reference Points
5.5 Monitoring Techniques

5.5.1 General Considerations
5.5.2 Equipment
5.5.3 Bioaccumulation

5.6 Variability and Reference Points
5.7 Collection of Ancillary Data
5.8 Sampling Design and Required Level of Sampling Effort
5.9 Summary

6. Birds as Indicators of Prairie Wetland Integrity

6.1 Ecological Significance
6.2 Potential Indicator Metrics
6.3 Previous and Ongoing Monitoring
6.4 Response to Stressors

6.4.1 Birds as Indicators of Hydrologic Factors
6.4.2 Birds as Indicators of Changes in Vegetative Cover
6.4.3 Birds as Indicators of Wetland Salinity
6.4.4 Birds as Indicators of Sedimentation and Turbidity
6.4.5 Birds as Indicators of Excessive Nutrient Loads and Anoxia
6.4.6 Birds as Indicators of Pesticide and Heavy Metal Contamination

6.5 Monitoring Techniques

6.5.1 General Surveys
6.5.2 Reproductive Success
6.5.3 Time Budget Analysis
6.5.4 Bioassay Methods
6.5.5 Bioaccumulation

6.6 Variability and Reference Points

6.6.1 Spatial Variability
6.6.2 Temporal Variability

6.7 Collection of Ancillary Data
6.8 Sampling Design and Required Level of Sampling Effort

6.8.1 General Considerations
6.8.2 Asymptotic Richness: Results of Analysis
6.8.3 Power of Detection: Results of Analysis

6.9 Summary

7. Synthesis and Recommendations for Indicators

Also available to download - Bioindicators for Assesing Ecological Integrity of Prairie Wetlands

8. Appendices Read online or download

Appendix A. Taxonomic Index: Plant Species Tolerances and Responses to Water Regime, Drainage, Land Use, Salinity, and Turbidity; Food Value to Waterfowl; Toxicity Data Availability
Appendix B. Taxonomic Index: Invertebrate Tolerances and Responses to Water Regime, Oxygen, Salinity, and Sediment; Food Value to Waterfowl
Appendix C. Taxonomic Index: Bird Wetland Type Associations, Relative Abundance, and Trends
Appendix D. Taxonomic Index: Published Field Studies of Plant-Salinity Relationships in Prairie Wetlands
Appendix E. Taxonomic Index: Published Field Studies of Plant-Water Regime Relationships in Prairie Wetlands
Appendix F. Taxonomic Index: Published Field Studies of Invertebrate-- Vegetation Cover Relationships in Prairie Wetlands
Appendix G. Taxonomic Index: Published Field Studies of Invertebrate-- Water Regime Relationships in Prairie Wetlands
Appendix H. Dominant Algae in Prairie Wetlands
Appendix I. Rare Wetland Plants Reported From Prairie Counties of North Dakota
Appendix J. Catalog of Published Biological Studies of Prairie Wetlands: Locations, Sampling Regimes, Key Variables, and Related Descriptors
Appendix K. Catalog of Ongoing Biological Studies of Prairie Wetlands: Locations, Sampling Regimes, Key Variables, and Related Descriptors
Appendix L. Descriptions of Data Sets Analyzed For This Report
Appendix M. Results of Power of Detection Analyses of Existing Prairie Data Sets
Appendix N. Library of Coefficients of Variation from Prairie Wetlands
Appendix O. Results of Asymptotic Richness Calculations Using Existing Prairie Data Sets

This document is designed to assist state agencies and other users in developing programs to monitor biological communities of prairie pothole wetlands and ultimately, to develop biological criteria appropriate for protecting this valued resource. The document emphasizes one aspect of biocriteria development: the selection (targeting) of assemblages of biological indicators (bioindicators) and metrics, as a basis for designing and conducting biosurveys. Before meaningful biocriteria can be developed and implemented, appropriate bioindicators must be identified and tested. Bioindicators are species, species assemblages, or communities whose presence, abundance, and condition is indicative of a particular set of environmental conditions.

As a foundation for developing biocriteria, the document compiles current knowledge regarding responses of various organisms to natural and anthropogenic stresses, and summarizes the utility of various organisms as indicators of these stresses. Information is organized according to major assemblages of related species: microbes, The document also reviews past and ongoing biological monitoring programs of the prairie region's wetlands, and from a limited number of existing data sets, provides quantified estimates of spatial and temporal variability of various biological s. As an additional aid to future monitoring, the document broadly describes field sampling methods potentially applicable to the region's wetlands. By documenting the ecological roles of each biological , the document also attempts to clarify understanding of interactions among ecosystem components and justify use of particular biological s as indicators. Several appendices of the document are in electronic format and provide a data base of information on environmental tolerances, life history, habitat preferences, and other characteristics of individual taxa, as well as tabulating results of the analyses of indicator variability.

The document concludes that in most prairie wetlands the possibility of ongoing or recent past exposure to excessive sedimentation is probably best indicated by species composition of algae and invertebrates, with emphasis on the epibenthic forms (organisms that live on the top surfaces of the sediment). Epibenthic and epiphytic algae and invertebrates are also useful indicators of excessive enrichment, removal of vegetative cover, and turbidity that is occurring either currently or during past years as determined by analysis of decay-resistant remains. Ongoing or recent past changes of water regime and salinity, as well as overgrazing, in individual wetlands are perhaps best indicated by species composition of vascular plant communities. Longer-term changes in these factors can be inferred by examining seed banks and decay-resistant remains of invertebrates. Exposure to pesticides and heavy metal contaminants can sometimes be inferred from species composition of invertebrates and from various biomarkers in amphibians and birds. For bioaccumulative contaminants, tissues of individual plants and birds can be examined. Birds are also uniquely valuable for spatially integrating information on the hydrologic stresses to wetlands across entire regions.

This document was prepared at the EPA National Health and Environmental Effects Research Laboratory, Western Ecology Division, in Corvallis, Oregon, through Contract 68-C4-0019 to ManTech Environmental Research Services Corp. It was subjected to the Agency's peer and administrative review and approved for publication. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.

Preferred citation:

Adamus, P.R. 1996. Bioindicators for assessing ecological integrity of prairie wetlands. EPA/600/R-96/082. Corvallis, OR: U.S. Environmental Protection Agency, Environmental Research Laboratory.

Acknowledgments

This effort was conducted in support of the Risk Reduction component of EPA's Wetlands Research Program. Mary E. Kentula was the EPA Project Officer. Brooke Abbruzzese and Stephanie Gwin were the project managers for ManTech Environmental Research Corporation (MERSC). William Sanville and Naomi Detenbeck of the USEPA Environmental Research Laboratory - Duluth, and P. James Wigington of the USEPA Environmental Research Laboratory - Corvallis, were instrumental in focusing the study objectives. Ted Ernst performed the statistical analyses. Carol Roberts helped prepare the figures. The document benefitted greatly from the review comments of Loren Bahls, Walter Duffy, Chip Euliss, Susan Galatowitsch, Mark Gloutney, Hal Kantrud, Gary Krapu, Mark Hanson, Judy Helgen, Henry Murkin, and Louisa Squires. Cynthia Chapman of MERSC edited the document. The statistical analyses presented in this document would not have been possible without suggestions from Scott Urquehart, Oregon State University, and the gracious sharing of data sets by the following scientists:

Sam Droege,
Breeding Bird Survey, National Biological Service, Washington, DC

Walter Duffy,
Cooperative Fish and Wildlife Research Unit, National Biological Service, Brookings, SD

Ned (Chip) Euliss and David Mushet,
Northern Prairie Science Center, National Biological Service, Jamestown, ND

Susan Galatowitsch,
University of Minnesota, Minneapolis, MN

Mark Hanson,
Minnesota Dept. Natural Resources, Bemidji, MN

Lawrence Igl and Douglas Johnson,
Northern Prairie Science Center, National Biological Service, Jamestown, ND

Henry Murkin,
Institute for Wetland and Waterfowl Research, Oak Hammock Marsh, Manitoba

Louisa Squires,
Santa Clara Water Resources District, San Jose, CA (formerly Iowa State University)

The following scientists were especially helpful in informing me of relevant ongoing studies during a visit to the Northern Prairie Science Center: Lew Cowardin, Ray Greenwood, Larry Igl, Gary Krapu, and Jeff Price.

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