APM 6D FY08 Interactions between stream nutrients and habitat alteration on water 
quality and aquatic life (WED). 
Critical Path 
Determining the role of essential habitat in maintaining fish, shellfish, and wildlife populations 
involves two distinct research components: 
1. Describing the relationship between habitat and biota at appropriate spatial scales and with 
sufficient detail and resolution to quantify the effects of both incremental and catastrophic habitat 
alteration; and 
2. Synthesizing the cumulative support function of individual habitats and ecosystems and 
integrating habitat alteration effects with effects of other stressors, so that resource protection and 
restoration priorities can be evaluated at spatial scales up to and including regions or large 
receiving bodies. 
Within these two research components, research efforts can be further categorized by spatial 
scale, ranging from habitats within ecosystems to entire ecosystems to landscapes and regional 
habitat mosaics. A critical path diagram illustrating this two-component research strategy and 
the spatial focus of research efforts is given in Figure 3. Table 1 gives a overall time-line for the 
overall plan. 
Component 1 
NHEERL proposes to focus research describing relationships between habitat and biota on 
coastal marshes, estuaries, and nearshore environments. Two primary spatial scales will be 
considered: the scale of habitat elements, especially vegetated habitat, within marsh and 
estuarine systems; and the scale of entire coastal wetland and estuarine ecosystems (i.e., micro 
and macro-habitat scale). Synthesizing the cumulative population support functions of coastal 
habitats and ecosystems on a regional basis is a long-term goal, but the initial emphasis will be 
on quantifying habitat-biota relationships at the ecosystem and within ecosystem scale. 
Necessary elements of this habitat research include: 
1. Identifying suites of endpoints that provide a nationally comprehensive and comparable basis 
for linking alteration of key coastal habitats to species and assemblages of economic or societal 
14 
