Compositing samples for beach monitoring is beneficial

Ann Arbor, MI — Beach managers analyze water samples for bacteria to decide whether or not a beach is safe for recreational use. Beach managers only analyze a sample from one site at the beach, which isn't representative of the entire beach; or alternatively, they collect and analyze samples from several sites across the beach.

"By combining several samples into a composite sample, beach managers can get a good representation of the beach's water quality and only have to analyze one sample," states Erin Bertke, a biologist at the Ohio Water Science Center U. S. Geological Survey.

Bertke and other researchers completed a study in 2005 at three Lake Erie beaches, which showed that composite analysis of bacteria from water samples was just as effective as separately analyzing several samples from the same beach and then averaging the results. Compositing samples led to less time needed to process samples and a cost savings.

Original Publication Information

Results of this study, "Composite Analysis for Escherichia coli at Coastal Beaches," are reported by Erin E. Bertke in the latest issue (Volume 33, No. 2, pp. 335-341) of the Journal of Great Lakes Research, published by the International Association for Great Lakes Research, 2007.

For more information about the study, contact Erin E. Bertke, Ohio Water Science Center, U. S. Geological Survey, 6480 Doubletree Avenue, Columbus, Ohio 43229; eebertke@usgs.gov, (614) 430-7712.

For information about the Journal of Great Lakes Research, contact Marlene Evans, Editor, National Water Research Institute, 11 Innovation Boulevard, Saskatoon, SK, S7N 3H5, Canada; editor@iaglr.org; (608) 692-1076.

Links

• The Article (abstract)
• Vol. 33(2) Table of Contents
• Searchable JGLR Archive
• IAGLR Web Site

Since 1967, IAGLR has served as the focal point for compiling and disseminating multidisciplinary knowledge on North America's Laurentian Great Lakes and other large lakes of the world and their watersheds. In part, IAGLR communicates this knowledge through publication of the Journal of Great Lakes Research, available to members in print and electronic form. A searchable archive of the journal is available online and includes the abstracts of articles from the journal's inception in 1975 through the most recent issue. In addition, complete articles are available to members who have signed up for an electronic subscription.