Environ. Sci. Technol., 42 (12), 4454–4460, 2008. 10.1021/es703038c
Web Release Date: May 8, 2008
Copyright © 2008 American Chemical Society
Coastal Strategies to Predict Escherichia coli Concentrations for Beaches along a 35 km Stretch of Southern Lake Michigan
Meredith B. Nevers and Richard L. Whitman*
U.S. Geological Survey, Great Lakes Science Center, 1100 N. Mineral Springs Road, Porter, Indiana 46304
Received for review December 5, 2007
Revised manuscript received March 14, 2008
Accepted March 25, 2008
Abstract:
To understand the fate and movement of Escherichia coli in beach water, numerous modeling studies have been undertaken including mechanistic predictions of currents and plumes and empirical modeling based on hydrometeorological variables. Most approaches are limited in scope by nearshore currents or physical obstacles and data limitations; few examine the issue from a larger spatial scale. Given the similarities between variables typically included in these models, we attempted to take a broader view of E. coli fluctuations by simultaneously examining twelve beaches along 35 km of Indiana’s Lake Michigan coastline that includes five point-source outfalls. The beaches had similar E. coli fluctuations, and a best-fit empirical model included two variables: wave height and an interactive term comprised of wind direction and creek turbidity. Individual beach R2 was 0.32−0.50. Data training-set results were comparable to validation results (R2 = 0.48). Amount of variation explained by the model was similar to previous reports for individual beaches. By extending the modeling approach to include more coastline distance, broader-scale spatial and temporal changes in bacteria concentrations and the influencing factors can be characterized.
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Meredith B. Nevers
Aquatic Biologist
U.S. Geological Survey
Lake Michigan Ecological Research Station
1100 N. Mineral Springs Rd.
Porter, IN 46304
phone (219) 926-8336 ext. 425 fax (219) 929-5792
mnevers@usgs.gov
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