Analysis of QA/QC Protocols and Value of Data to the Development of Reference Criteria in the Georgia Ecoregions Project

2005·9.7 MB·English

by  Ferring, Tracy Jo

Columbus State University
College ofScience
The Graduate Program in Environmental Science
Analysis ofQA/QC Protocols and Value ofData to the Development of
Reference Criteria in the Georgia Ecoregions Project
A
Thesis in
Environmental Science
by
Tracy Jo Ferring
Submitted in Partial Fulfillment
ofthe Requirements
for the Degree of
Master ofScience
December 2005
2005 by Tracy Jo Ferring
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I have submitted this thesis in partial fulfillment of the requirements for the degree of
Master ofScience.
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approve the thesis ofTracy J. Ferring as presented here.
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Date ies A. Gore
'rofessor ofEnvironmental Science,
Policy, and Geography
Thesis Advisor
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Date George E. Stanton
Dean ofScience
Professor ofBiology
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Date Harlan J. Hendricks
Associate Professor ofBiology
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Abstract
The concept of Measurements Quality Objectives (MQOs), in bioassessment
programs is a useful tool in evaluating the consistency ofdata and limiting variability and
potential sources of measurement error. Typical evaluations of data repeatability
and/or data quality center on the use ofa series ofcalculations that quantify variability
between measures. These calculations provided some indication ofnot only the quality of
the data collected, but also acted as a measure of how representative the biological data
were to each ecoregion. The evaluation of the Quality Control data for this project
provides a framework for data users and water resource managers to assess the reliability
and inherent variability ofthe proposed biotic indices for the state ofGeorgia.
In bioassessment programs, it is important to identify natural variability of
reference and impaired sites, as well as the variability of the influences anthropogenic
stressors. Calculations of variance within the biological parameters measured are
necessary for identifying the effects of measurement errors and/or inherent differences
between sampling sites in relation to the overall variance of a metric or index on an
ecoregional and sub-ecoregional level.
Considering the invertebrate data produced by the Georgia Ecoregions Project,
the consistency of all metric categories having average precision measures above the
prescribed MQOs for both raw metric values and standardized metric scores may
demonstrate that the lotic systems across the state of Georgia naturally have high
variability from year-to-year and spatially within catchments. This in turn may indicate
that the established precision thresholds ofthe MQOs may not be indicative of the data
quality for this specific project.