Interaction of ambient conditions and fecal coliform bacteria in southern Lake Michigan beach waters: Monitoring program implications
Natural Areas Journal
By: Richard L. Whitman, Meredith Becker Nevers, and Paul J. Gerovac
Links
- More information: Publisher Index Page
- Download citation as: RIS | Dublin Core
Abstract
Excessive fecal coliform bacteria in public swimming waters can potentially threaten visitor health. Fecal coliform bacteria (1984-1989) and Escherichia coli (1990-1995) density were monitored weekly at the Indiana Dunes National Lakeshore beaches for 12 summers, and park officials closed swimming areas when fecal coliform density exceeded the state water quality criteria (400 CFU fecal coliforms/ 100 ml; 235 CFU E. coli/100 ml water). Due to a 24-hour incubation in the fecal coliform and E. coli assays, beaches were closed the day after collection of high fecal coliform. Our analysis suggests that it is not possible to predict one day's fecal coliform count based on the previous day's results in waters taken from southern Lake Michigan beaches. Dispersal and deposition of bacteria were not uniform among sites or across time apparently due to interactions among environmental variables including rainfall, wind direction, water temperature, and bacteria source. Rainfall combined with northwest winds increased bacteria concentrations. Escherichia coli followed a seasonal trend with similar fluctuations in density among beaches. We suggest that the current beach monitoring protocol is inadequate for predicting fecal coliform density at the time of beach closure, and, subsequently, its use for ensuring visitor safety remains questionable.
Suggested Citation
Whitman, R.L., Nevers, M.B., Gerovac, P.J., 1999, Interaction of ambient conditions and fecal coliform bacteria in southern Lake Michigan beach waters: Monitoring program implications: Natural Areas Journal, v. 19, no. 2, p. 166-171.
Study Area
| Publication type | Article |
|---|---|
| Publication Subtype | Journal Article |
| Title | Interaction of ambient conditions and fecal coliform bacteria in southern Lake Michigan beach waters: Monitoring program implications |
| Series title | Natural Areas Journal |
| Volume | 19 |
| Issue | 2 |
| Year Published | 1999 |
| Language | English |
| Publisher | Natural Areas Association |
| Contributing office(s) | Great Lakes Science Center |
| Description | 6 p. |
| First page | 166 |
| Last page | 171 |
| Country | United States |
| State | Indiana |
| Other Geospatial | Indiana Dunes National Lakeshore, Lake Michigan |