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. The four classes include sites affected 
by nutrients only, toxic chemicals only, both nutrients and toxic chemicals, and neither nutrients 
nor toxic chemicals. A candidate suite of biological indicators would then be developed that 
demonstrates differential sensitivity to either stressors. This would require examination of 
historical effects databases and population or community response data as well as receiving input 
on single-stressor response models for nutrients and toxic chemical efforts (see Sections 5 and 7). 
In collaboration with AED, lab or field tests will be used to validate the sensitivity of these 
indicators in each of the four classes of sites. If historical data exists for indicators in the study 
areas, tests will confirm the sensitivity of indicators to these two stressors. Multivariate analysis 
methods will be applied to allocate variation in the response indicators to differentiate between 
nutrient and toxic effects. 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. GED and AED will coordinate the development of models within the 
context of the classification framework and diagnostics. 
4. Coordination with other Goal 2 Research (WED). 
The freshwater habitat alteration group at WED is developing a project to examine the influence 
of human activities on native fish habitat at reach, watershed, and landscape scales. This group, 
led by Jim Wigington, is developing salmon and native fish assemblage modeling approaches 
while concurrently evaluating the interactive influences of flow, temperature, physical habitat, 
and nutrients on salmon and native fish. This project is focused on coastal drainages of Oregon 
where there is a great opportunity to contribute to the restoration of salmon populations through 
cooperative research efforts with State (Oregon Department offish and Wildlife, Department of 
Environmental Quality) and other Federal agencies (NMFS, U.S. Forest Service). 
5. Coordination with GPRA Goal 8 (AED, GED, MED, WED). 
Goal 2 activities under Diagnostics will be coordinated with Goal 8 activities in monitoring and 
assessment through the EMAP program. There are currently monitoring initiatives underway 
through: 1) the Coastal Initiative, examining the condition of marine estuaries; 2) the STAR 
grants program to develop indicators for coastal freshwater and marine systems, (including the 
GLEI cooperative agreement for indicator development on coastal Great Lakes systems); 3) 
Western EMAP (including coastal watersheds in the states of Washington, Oregon, and 
California as intensive monitoring sites); and 4) a variety of Regional EMAP projects. The latter 
program currently emphasizes watershed-scale approaches to monitoring and assessment. For 
example, a recently initiated REMAP project with the state of West Virginia will demonstrate 
both the development of a watershed classification system and test thresholds of land-use/land- 
cover along gradients of disturbance (related to forestry, agricultural, development, and mining 
activity), while at the same time developing fish indices of biotic integrity. 
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