Date of Graduation

Spring 2016

Document Type

Honors Research Project

Degree Name

Bachelor of Science

Major

Biology

Research Sponsor

Mark Citriglia

First Reader

Angela Hartsock

Second Reader

Kristen Greenwood

Abstract

To provide more timely estimates of indicator bacteria concentrations in recreational waters, environmental agencies are using predictive models to supplement conventional bacteria enumeration methods. As a tool to develop predictive models, correlational relationships between variables can be examined, to determine the statistical significance of explanatory variables. Prior research at Lake Erie beaches suggests that environmental conditions such as average wave height, rainfall, turbidity, and water temperature may demonstrate a strong relationship to concentrations of fecal indicator bacteria Escherichia coli and Enterococcus faecalis (enterococci). These relationships were examined at Edgewater Beach in Cleveland, Ohio, using statistical correlation tests on data collected from field measurements and analyses of lake water samples during the 2015 recreational season. E. coli concentrations were determined by analyzing samples prepared using EPA Method 9223B for Colilert-24®/Quanti-tray®. Enterococci concentrations were quantified by analyzing cultures prepared by EPA Method 1600 for membrane filtration of lake water samples. Additionally, ANOVA tests were used to examine the relationship between concentrations of fecal indicator bacteria and wave height. Results of the correlation tests demonstrated that water turbidity had the most significant correlation to E. coli and enterococci concentrations. Results of the ANOVA tests indicated that mean concentrations of bacteria associated with the highest wave heights was significantly greater than mean concentrations at lower wave heights. A weaker correlation was demonstrated in the relationships of bacteria concentrations to water temperature and antecedent rainfall. These results can provide insight on exploring potential variables to use in future regression models for examining indicator bacteria concentrations at Edgewater Beach.

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