Bird Counts Predict E.Coli In Beach Water Better Than Bird Droppings
Ann Arbor, MI — Birds and beach water quality do not mix. Suspected sources of bacterial contamination found at many beaches include human sewage, agricultural runoff, and feces from wildlife and domestic animals, depending on beach location. Birds such as gulls and geese have been suggested as a primary source of fecal contamination at many beaches, but proving that bacteria are directly from birds is difficult to predict.
Beach managers often rely on once-daily birds counts to measure the impact of waterfowl on beach health. Yet since bird populations at many beaches are transitory, this study involved counting avian waste material along beaches in the hope to use these counts as a predictor of Escherichia coli (E.coli) amounts in beach water. Researchers investigated 13 rural and semi-urban beaches, counting avian waste three times per week during the summer swimming seasons of 2004 and 2005.
They found that E.coli levels in beach water did not correspond to waste counts at the beaches. However, overall numbers of birds were positively correlated with E. coli concentrations in beach water at 30% of the beaches in 2004 and at one of 13 beaches in 2005 (showing only a weak relationship).
"The amount of gull or goose feces on a beach did not appear to be a determining factor in E.coli levels in the beach water during the same day as a waste count, or during the following day," states Gregory Kleinheinz, an Associate Professor of Microbiology at the University of Wisconsin - Oshkosh.
These results indicate that neither avian waste counting, nor overall number of birds can successfully be used to predict microbial contamination of recreational beaches at many beaches. However, the use of additional bird counts (more than once daily) may serve as a better predictor of E.coli contamination than the waste they leave behind.
Original Publication Information
Results of this study "Evaluation of Avian Waste and Bird Counts as Predicators of Escherichia coli Contamination at Door County, Wisconsin Beaches," are reported by Gregory T. Kleinheinz, Colleen M. McDermott and Vinni Chomeau in the latest issue (Volume 32, No. 1, pp. 117-123) of the Journal of Great Lakes Research, published by the International Association for Great Lakes Research, 2006.
Contacts
For more information about the study, contact Gregory Kleinheinz, Department of Biology & Microbiology, Halsey Science Center, University of Wisconsin-Oshkosh, Oshkosh, WI 54901; email kleinhei@uwosh.edu; phone (920)424-1100.
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
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.
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