found. No nonindigenous macrophyte species were observed at California sites, except 
one high marsh site in San Francisco Bay. 
Shoreline land use adjacent to sample sites showed much higher percentages of 
urban shoreline in California and San Francisco Bay than in Washington and Oregon. 
Much of the undeveloped land in the latter two states was in silviculture. Surprisingly, 
estimates of residential shoreline in the three states were relatively similar. 
The study showed that further refinements of measurement approaches for plant 
community and shoreline development indicators are needed. Quadrat and transect 
sizes selected for plant community assessment proved too small for effectively 
capturing plant diversity at sample sites. While it was believed that available habitat 
maps for the west coast were insufficiently accurate to establish marsh-type strata for 
the sampling design, this proved false, and partitioning of sampling effort by habitat 
across the region may have improved the assessment. Better guidance on shoreline 
development classification is required to reduce variance among field crews. In spite of 
the costs for processing benthic samples with high levels of organic materials, 
volumetric sub sampling is not recommended because of the problems produced in 
intercomparison of data among sites for benthic community metrics. 
The results of this assessment study represent the first regional scale survey of 
the condition of intertidal wetland habitats on the West Coast. Findings confirm results 
from previous National Coastal Assessment studies of West Coast estuaries that have 
shown that sediment contamination issues are limited in extent, but that West Coast 
estuaries have been broadly invaded by nonindigenous species. 
XVI 
