different layers of cover. For rooted species, the blade length of the longest blades was 
measured. The total biomass of each species of rooted plants and each type of algae in 
the quadrat was determined by cutting all vegetation at the sediment surface, sorting by 
species, and obtaining the dry weight (g dry weight) of biomass for each species. 
Plants were dried in the laboratory until they reached constant dry weight at 80 C. Plant 
composition and cover were also estimated using 25 random points along a 5-meter 
transect. Each plant species or open ground noted at the 25 random points along the 
5-m transect was recorded, with the possibility of more than one plant species occurring 
at each point. In all cases, seagrasses and other rooted plants were identified to 
species if possible, or to the lowest practical taxonomic level. If the species of plant was 
not known with certainty by the field crew, a reference specimen was taken by the field 
crew for identification by a qualified plant taxonomist. 
2.2.4 Surficial Sediment Sample 
At each site, surficial sediment layer (top 2-3 cm) was collected by spatula or 
scoop from one of the 0.25-m 2 quadrats to provide sediment for the analyses of 
inorganic and organic chemical contaminants, total organic carbon (TOC), and grain 
size determinations. Surficial sediment was combined in a clean, high-grade stainless 
steel or Teflon vessel and composited by stirring well to ensure a homogenous sample 
before sub-samples for the various analyses were taken (Table 2.2.1). 
2.2.5 Sediment Pollutant and Nutrient Analysis 
Sediment collected from each site was analyzed for a suite of organic pollutants, 
metals and interstitial nutrients (Table 2.2.1). Fifteen metals were analyzed in all three 
states. California quantified sediment metals including mercury using inductively 
coupled plasma mass spectrometry (ICPMS). Washington quantified all metals except 
mercury using ICPMS, and used cold vapor atomic absorption (CVAA) for mercury. 
Oregon quantified all metals except mercury using inductively coupled plasma atomic 
emission spectrophotometry (ICPAES) and CVAA for mercury. For organic pollutants, a 
total of 21 PCB congeners (PCBs), DDT and its primary metabolites, and 14 chlorinated 
pesticides were measured. There were 21 polycyclic aromatic hydrocarbons (PAHs) 
measured by all three states out of the 23 target compounds (Table 2.2.1); 
phenanthrene and dibenzothiophene were not measured by all three states. California 
and Washington used GCMS to quantify the PCBs, DDTs, pesticides, and PAHs. 
Oregon used GCECD for the chlorinated compounds and GCMS for the PAHs. 
California quantified total nitrogen using EPA method 415.1 while Oregon and 
Washington used CHN analyzers. All three states used ICPAES to quantify total 
sediment phosphorus. Total organic carbon (TOC) was analyzed in Washington by 
combustion and CHN analyzers while California and Oregon used CHN analyzers. 
2.2.6 Benthic Infaunal Samples 
The objective was to collect a 0.1-m 2 benthic infaunal sample to a depth of 10 cm 
at all sites, with the sample processed through a 1.0 mm mesh sieve. A specially 
designed post-hole corer sampler was constructed to assist in obtaining these intertidal 
benthic samples, though other sampling methods were acceptable if they had the same 
nominal area as the post-hole sampler. During the course of the survey, however, it 
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