Specifically, for the “fixed station" samples both “total_score" and “grand_score" records are 
reported within the Chesapeake Bay Information Management System (C1MS) 3 . "Totalscore" 
records are replicate measurements of the same community event; the average of these is 
reported as the “grand score." The Chesapeake Bay benthic experts (R. Llanso, Versar Inc., 
Pers. Comm. 2009) recommended using the “grand score" in the Chesapeake Bay dissolved 
oxygen criteria assessment analyses to avoid errors not accounting for the replicate results of a 
sampling event. By comparison, random station records in the CIMS database report only a 
“total score" as the sampling event B-1BI measure; no “grand scores” will be found associated 
with random station data records. 
SUMMARY OF RECOMMENDATIONS 
Based on the findings of the analyses and in accordance with the STAC (2009) 
recommendations. Table III-l summarizes the revisions to the methodology for identifying 
dissolved oxygen biologically-based reference curves for Chesapeake Bay water quality criteria 
attainment assessments (Table III-l). 
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