Impact/Purpose:

The objectives of this research are to develop diagnostic tools for single and multiple stressors; develop forecasting models; illustrate the application of diagnostic methods, tools and models for single and multiple stressors, including forecasting models; provide input to regional decision-support systems; demonstrate how assessment results can be extrapolated across regions, watersheds, and water bodies, and biological levels of organization; and illustrate how stressor-response relationships vary among different classes of systems in a predictable fashion.

These studies will enable OW to understand how multiple stressors, such as nutrients and toxic chemical loadings, affect important habitats separately and in combination for several types of coastal ecosystems across the U.S. We expect the methods and models developed here to be generic for specific stressor-ecosystem combinations. Therefore, we predict that they can be applied in other regions that contain similar stressor-ecosystem combinations. Classification schemes will allow us to regionalize results and recommendations for TMDLs and watershed restoration activities. The scientific approach used here is also generic and it could be applied to develop similar relationships for the ecosystems and stressors that predominate in any region.

APMs scheduled for FY05 and FY08 delivery, will result in the development of the first generation of diagnostic tools and equip clients with such tools to determine impairment causes, respectively.. In addition, development of diagnostic tools includes a Toxicity Identification Evaluation guidance document which is a FY04 APG.

Description:

Case studies are a useful vehicle for developing and testing conceptual models, classification systems, diagnostic tools and models, and stressor-response relationships. Furthermore, case studies focused on specific places or issues of interest to the Agency provide an excellent mechanism to address high priority environmental problems, including the development of TMDLs. Diagnostic case studies provide a mechanism for developing, testing, and applying methods and models for distinguishing among single aquatic stressors and allocating cause among multiple stressors. Regional case studies provide the basis for verifying the efficacy of these diagnostic tools. Several case studies will be performed to incorporate the habitat, ecosystem, watershed, and regional spatial scales as well as the organismal, population, community, and ecosystem levels of biological organization. Within the Atlantic Ecology Division, the case study underway includes development of a Pollutant Identification Evaluation (PIE) approach. PIE is a four phased approach which includes a screening phase to analyze existing data; a phase to establish that a source, stressor and effect exists; a phase that ensures that the source, stressor and effect are linked; and finally a confirmatory phase. Development of the PIE has allowed us to identify and perform preliminary research on diagnostic tools and to use existing datasets to determine if the approach is feasible. We have also identified a study area for the case study and will initiate our first field season in 2004. A case study will be carried out within the coastal ecosystems of the Gulf of Mexico, particularly the Pensacola Bay and neighboring coastal systems in Regions 4 and 6. Pensacola Bay has the critical attributes for a case study: many waters are designated as impaired, multiple stressors cause impairments, a historical database exists, and there is potential for extrapolation to other watersheds/estuaries. Again, two stressors will be emphasized initially: nutrients and toxic chemicals. The first step in the approach will be to examine existing 303(d) impairment lists, databases on nutrients and toxic chemicals, and land use/land cover characteristics for Gulf of Mexico estuaries to delineate four classes of sites based on observed effects or criteria. A candidate suite of biological indicators would then be developed that demonstrates differential sensitivity to either stressor. Lab or field tests will be used to validate the sensitivity of these indicators in each of the four classes of sites. Modeling approaches will then be used to integrate individual and interactive effects of nutrients and toxic chemicals on biological indicators. Models would account for population and community levels of response across the four classes of sites and along stressor gradients. To date, a State of the Bay report has been completed, a National Coastal Classification has been developed, and historical data have been compiled. The Pollutant Identification approach will be used to diagnose single and multiple stressors causing biological impairment to coastal watersheds. Data will be organized and evaluated to reveal and quantify associations between source, stress and biological impairment to aquatic ecosystems. Future research will address the need for better diagnostic indicators of biological impairment, and will consider classification in estimating the probability of impairment for coastal waters. The Gulf Ecology Division established a memorandum of understanding with FL DEP to produce a State of the Bay report assessing the condition of Pensacola Bay. Historical databases were generated for coastal watersheds including Pensacola Bay from sources that include FL DEP, EPA EMAP, and NOAA CA&DS. Data collected pertains to 1) physical and hydrological parameters, 2) land cover statistics, 3) stressor loads, 4) in situ stressor concentrations, and 5) modifying factors. The Mid-Continent Ecology Division's approach to diagnosing causes of impairment in Great Lakes coastal ecosystems through case studies uses a phased, three-stage approach, and is linked with the Division's research efforts for habitat, nutrients, and Great Lakes near-shore ecosystems. Our diagnostics research began as a Great Lakes wide assessment of stressor-responses to nutrient, sediment and toxic loadings to riverine and protected coastal wetlands. The second phase of this research is a "headwaters to receiving waters" study of Lake Michigan's Muskegon and Grand River basins. The goal of this phase is to monitor the strength and fidelity of stressor-response relationships across broad resource classes at the basin scale. The final phase will be a more temporally-intensive monitoring of Lake Superior's St. Louis River and Estuary in order to understand the subtleties of stressor-response relationships through time and in a lower stress environment. The Muskegon, Grand, and St. Louis Rivers basins span an agricultural/chemical gradient that is indicative of similar nutrient and clean sediment enrichment gradients throughout the Great Lakes. Toxic sediments are common in these basins. Habitat loss gradients, although not as well studied, are representative of those found throughout the Great Lakes basin. We will assess the responses of fish, macroinvertebrate, and algal assemblages to these stressors. Our efforts are linked with the Atlantic and Gulf Ecology Divisions' diagnostic research efforts through an adherence to overall goals, developing and sharing common approaches, and jointly testing case studies for differentiating biological impairment from single and multiple stressors in coastal ecosystems.

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