thresholds of concern exist, e.g. dissolved oxygen concentration < 2.3 mg/L, percentiles 
are reported for such values. Where thresholds of concern have not been developed, 
e.g., the benthic variables, indicator values that represent common reporting values for 
frequency distributions (e.g., the median, 90 th percentile, upper and lower quartiles), are 
presented. Data presented graphically in this report are primarily in the form of CDFs, 
pie charts, and simple bar graphs representing the mean +1 standard deviation of the 
indicator values. 
2.7 Sampling, Data Integration, and Data Quality Issues 
The initial effort to develop a sampling frame representing only soft-sediment 
areas of the West Coast was generally a success, and a limited number of stations 
within the EMAP cruise effort had to be abandoned as a result of encountering rocky 
bottom. Primarily this occurred in the Strait of Juan de Fuca (Section 2.1 above), and 
the frame definition was adjusted a posteriori to remove this area. There were two 
additional stations abandoned on the Washington shelf, no stations were abandoned on 
the Oregon shelf, and two stations were abandoned on the California shelf as a result of 
encountering rocky bottom. All abandoned stations were replaced with alternate 
stations from the initial sampling design. 
During the Oregon leg of the EMAP cruise, there were malfunctions of the CTD 
sensors which affected data for temperature, salinity, depth, and dissolved oxygen at 
numerous stations on the Oregon shelf. Questionable data due to equipment 
malfunction were flagged in the database and removed from data analyses. All Oregon 
Total Suspended Solids (TSS) data were flagged as questionable and removed from 
analyses. Filters for TSS appear to have been inadequately washed to remove salt 
crystals. 
While the Bight ’03 and NCA-West/EMAP studies were both designed as 
probability-based surveys, and the initial presumption was that data could be easily 
merged, the studies were executed and managed separately, and some data integration 
and compatibility issues arose as a result. For example, water-column nutrient samples 
were not collected at all Bight ’03 stations within the target depth range for the NCA- 
West/EMAP survey. For those samples collected, only nitrate and nitrite were 
analyzed, whereas the NCA-West/EMAP samples were analyzed for nitrate, nitrite and 
ammonium, and thus the studies were not directly comparable for total dissolved 
nitrogen. Tissue contaminant samples of demersal fishes were generally not collected 
under the Bight ’03 program. In the case of some multi-density categories, the Bight ’03 
program was unable to sample the target number of primary stations called for in the 
sample design, and no alternate stations were occupied. Thus the multi-density 
category weights for the data analysis were adjusted based on the actual number of 
stations occupied. 
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