This work will primarily be conducted in the Pacific Northwest, but the hydrogeomorphic 
classification being tested in Great Lakes coastal wetlands is based on hydrologic connectivity of 
wetlands to adjacent lake habitats and their watersheds, so many of the same habitat connectivity 
issues are relevant to the Great Lakes studies and will be implicitly incorporated into their design. 
In the Pacific Northwest, the approach to examining the effects of network structure and 
connectivity will be to build a spatially explicit network data structure that includes habitat 
quality and connectivity attributes and which can be linked to specific biological resptxise 
models. Such a network structure could be used in a number of ways. For example, it might be 
desirable to conduct simulations of several specific drainage networks, and to compare results 
between basins with high habitat quality and low habitat quality. Alternatively, it might be 
desirable to examine the effect of certain watershed characteristics (e.g., slope, catchment area, 
stream doisity) on fish dynamics by systematically varying those characteristics using synthetic 
landscapes. 
Biological Response of Fish to Habitat and Stream Network 
EPA has responsibilities under the CWA to restore and maintain the biological integrity of the 
nation’s waters. Therefore, it is desirable to understand how activities aimed at managing 
salmon would affect other fish species, in particular, native fish. To address these needs, field 
research and modeling efforts will be developed to examine how management actions would 
affect dynamics of various fish groups. This may include modeling at different levels of 
organization. First, species-level models would examine the biological response of particular 
species to watershed and network structure. Models would be run separately for salmon and 
possibly a few other species representative of different life history strategies. This will allow us 
to examine how salmon and fish with different habitat needs respond to a common set of 
management actions. Second, the biological response modeling could also include exploratory 
assemblage-level modeling. In this case the dynamic behavior being tracked is overall species 
richness, rather than abundance of a particular species. This allows us to examine community- 
level response to management actions. 
Products 
APM 2A FY03 Prototype watershed-stream network modeling approach for Pacific salmon 
(WED). 
APM 3C FY04 Report characterizing the relationship between habitat in stream networks and 
salmon-native fish for coastal Oregon watersheds (WED). 
APM 6A FY04 Ecological consequences of marine derived nutrients and nutrient enrichment for 
aquatic biota and stream habitat quality, with an emphasis on salmon and native fish (WED). 
APM 4A FY05 Develop indices of watershed integrity based on land use/land cover and 
relationships to fish (WED, MED). 
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