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Aquatic indicators of ecological condition and diagnosis


Development of improved biological, physical and diagnostic indictors for use in aquatic assessments, with a particular emphasis on improving the indicators implemented in the National Aquatic Resource Surveys (NARS), and integrating sustainability principles into indicator development.

Rationale and Research Approach:

The EPA Office of Water and the states currently use a limited number of biological, chemical, and physical indicators to assess condition and quantify stressors in NARS and similar assessments. EPA developed most of these indicators as part of the Environmental Monitoring and Assessment Program more than a decade ago, and their sophistication has been limited by the lack of an ongoing research program to investigate several critical aspects of aquatic indicators. This task will focus on solving some of the challenges presented by aquatic condition assessments, both old--quantifying reference conditions, analyzing complex taxonomic information, diagnosis of impairment, quantification of difficult-to-measure stressors--and new--quantifying sustainability, assessing climate change effects. This work will focus on a broad set of aquatic resources (lakes, streams, rivers, wetlands, estuaries) and include both indicators of ecological condition stressor diagnosis.

This task will include research on these emerging areas of indicator development:

1) Research on biological indicators for large systems (large lakes, rivers, estuaries)--large systems pose unique challenges in monitoring their biological, chemical and physical habitat integrity in  NARS, both because of sampling limitations, and because so few of these large systems are in their original (reference) condition. This task focuses on improving biological indicators, and their interpretation, for large lakes, rivers and estuaries. ORD has responded to recent regional requests to apply integrated approaches to address water and watershed problems of particular concern to Regions 5 and 9. A Lake Tahoe effort involves application of MED’s novel approach to efficiently characterize the nearshore of large lakes using rapid, synoptic in situ towing technology; survey information will measure water quality and plankton, as related to nutrients and sediments which significantly affect water clarity. MED and partners’ subsequent spatial analysis of nearshore water quality as related to contributing watersheds will directly inform the current implementation phase of a Lake Tahoe Basin TMDL. The effort is based on a request for application from Region 9.

The Coordinated Science and Monitoring Initiative (CSMI) is a bi-national effort to address pressing issues identified by the resource management community of the US/Canadian Great Lakes. A 2011 sampling effort, led by MED, coordinated several agencies to assess the condition of the whole of Lake Superior--linking surveys of water quality, plankton, intermediate prey species, and fish in one efficient statistical survey design, for the first time ever, from shore to offshore. The information will enable more sound approaches to ecosystem management of the lake as related to its basin. The effort is based on a request from the Lake Superior Work Group of the Bi-National Executive Committee.

2) Indicators of invasive species and their effects on the ecological condition of the systems they invade, with a particular emphasis on ballast water. Invasive species in vulnerable coastal harbors threaten the ecological and economic vitality of the Great Lakes basin. MED has been assisting EPA Region 5’s Great Lakes National Program Office (GLNPO) and the Great Lakes Restoration Initiative in optimizing survey/sampling designs and development of a broad network for early detection of current/future invasive species threats to sustainability. 2012 efforts tested designs in additional locations to enable consideration of design aspects and detection probabilities possible for a broad network. These assistance efforts, involving application of assessment tools in actual case practice, relate strongly to companion research efforts on watershed and water sustainability indicators, yet push the application of our emerging methods.

3) Development of monitoring methods that separate causal stressors from correlated or confounding factors in the environment, with a feedback loop to respond adaptively to changing environmental conditions. Indicators that can provide insights into the reasons driving biological degradation can also be used to prioritize management actions, and evaluate success. We will use a combination of case study development and literature review to identify indicators useful for causal assessment that can be incorporated into monitoring programs.

4) Quantification of the Biological Condition Gradient (BCG), and use of the BCG in setting expectations for the condition of aquatic resources.

5) The use of DNA sequence data (DNA barcoding) to identify the constituents of aquatic communities coupled with advances in DNA sequencing technology (Next Generation Sequencing, or NGS) allows researchers to provide clearer, more complete depictions of the biota in aquatic ecosystems (freshwater, marine, estuarine, or wetland), including previously under-studied, but likely important indicator groups such as meiofauna and periphyton. These new genetic/genomic techniques have the distinct potential to provide more detailed characterizations of the biota at sampling sites with increased speed and likely less expense than traditional monitoring practices. With the ability to identify a much greater segment of the community, these techniques create opportunities for developing new biotic indicators of key drivers and pressures related to sustainability and resiliency.

6) Integrating measured and modeled data in estimating stressor indicators that cannot currently be implemented in synoptic surveys (e.g., pesticide exposure, hydrologic alteration).

7) Using stable isotopes in aquatic and biological media to improve the identification of stressors and causes of impairment.

MED Scientists:

Anett Trebitz
Tim Corry
Jill Scharold
Anne Cotter
Sam Miller
Greg Peterson
Peder Yurista
Joel Hoffman


Negus, M.T. and J.C. Hoffman. 2013. Habitat and diet differentiation by two strains of rainbow trout in Lake Superior based on archival tags, stable isotopes, and bioenergetics. Journal of Great Lakes Research 39:578-590.

Expected Products:




Sep 30, 2013 1.1.B.1 Report evaluating biological indicators in large systems (microbes, algae, vegetation, macrobenthos and fish in large lakes, rivers, estuaries, wetlands). Joel Hoffman

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