FISH/SHELLFISH/WILDLFE 
- 
FOODWEBS 
- abundance 
- productivity 
- species conposition 
Indirect Effects: 
- ffophic structure (levds. 
-guildstructure -%exotics 
pathwQ5?s, etc.) 
- population structure 
- food abundance 
- food con^osition 
- corrpetition 
A 
Direct Effects: 
- shelter 
- spavaing substrate 
- physiolos^ limits 
Direct Effects: 
- habitat for pr^ ori^inisms 
- primary production 
- disturtence regime 
A 
HABITAT COMPONENTS VULNERABLE TO ALTERATION 
Sediments 
U^ter ciualitv 
Plants 
Morphologv 
-grain size 
-DO 
-growth form 
-area 
-% ori^nic 
-pH 
-areal erient 
-bathymetry 
-turbidity 
-biomass 
-channel vs. backwater 
-temperature 
-species 
Figure 4. Components of coastal vegetated habitat with possible pathways for direct and indirect 
effects of habitat alteration on fish, shellfish, and wildlife. 
so as to preclude duplication of effort, allow the differing objectives of the agencies to be 
represented (e.g., utilization vs. conservation), and foster synergy. As an example, both the 
South Atlantic Fishery Management Council and the Atlantic States Marine Fishery Commission 
have explicitly identified submerged aquatic vegetation (SAV) as areas of concern with respect 
to fishery resources, and EPA research efforts will be coordinated with those entities. Research 
on endangered species, such as Pacific salmonids, will necessitate close collaboration and 
coordination with other agencies, because authorization for and logistics of discrete, stand-alone 
efforts may be difficult or impossible. Additionally, a number of existing EPA or other Federal 
and State databases and software (e.g., those available at http://www.epa.gov/OW/soft.htiTil) may 
be useful during the implementation of this research. 
Assessment of Key Habitat Elements for Biota of Vegetated Aquatic Systems 
Assessing effects of incremental habitat alteration on species requires quantitative understanding 
of a given organism's reliance upon vegetated aquatic habitat. For clarity, this step is listed 
separately from the step of identifying candidate organisms, but at least a partial assessment of 
vegetation dependency will be done concurrently with species identification and prioritization. 
This step will integrate data from ongoing or published research, but EPA field efforts for some 
species, ecosystems, and habitat types will be required. It is necessary to critically evaluate the 
nature and level of the organism's dependence on vegetated habitat, both with respect to life 
history stages and the importance of vegetated habitat relative to alternative habitats. For 
21 
