[Date Prev][Date Next][Date Index]

GLIN==> Beach Closings

Posted on behalf of Irene Miles <miles@uiuc.edu>

Beach Closings
May 31, 2002

Source:    Charles Tseng (219)989-2403

           Leslie Dorworth (219)989-2726

Contact: Irene Miles
Extension Communications Specialist
(217)333-8055; miles@uiuc.edu

E.coli DNA Fingerprinting May Lead to Fewer Beach Closings

After a cold and wet spring, it is finally time to get to the serious
business of going to the beach. However, water contamination, which happens
with some frequency during the summer along the southern Lake Michigan
shoreline, can lead to beach closings and cancelled plans.

Illinois-Indiana Sea Grant (IISG) scientists are using the precision of DNA
fingerprinting to pinpoint sources of E.coli that can lead to water
contamination and beach closings. In Lake Michigan, high levels of E.coli
are the main cause of area beach closures during the summer.

By knowing the exact source of the outbreaks, municipalities can direct
their prevention efforts where they may be most effective. This knowledge
may also help local officials as they assess the risk of an outbreak. New
thinking holds that wildlife bacteria is less of a health threat to people
than bacteria from other humans.

Charles Tseng and Evert Ting, biologists at Purdue University Calumet, have
tracked the specific host species from over 500 E.coli samples.

"These E.coli DNA fingerprints of known sources will be used to determine
the source of E.coli from environmental samples. To date, DNA fingerprints
of over 600 insolates from beach sand and lake water have been prepared,"
said Tseng. "The goal is to create a comprehensive E.coli database that will
eventually have over 1,000 samples."

E.coli is a bacterium found in the digestive tract of humans, farm animals,
birds and
other wildlife animals. When the bacterium is detected in water in
significant numbers it indicates fecal contamination. While E.coli itself is
harmless in most cases, its presence indicates that more harmful bacteria
are also likely to be present in the water.

"Children, senior citizens and those who have weakened immune systems are
most at risk from these bacteria," said Leslie Dorworth, IISG aquatic
ecology specialist, at Purdue University Calumet, who is also IISG's
representative on the E.coli Interagency Task Force, and its outreach chair.

"High E.coli counts are frequently caused by overflowing storm-water and
sewage systems.  Sewage treatment plants often do not have sufficient
capacity to retain and process excess water from heavy rains," explained

But, she added, many times we have beach closings when there is little rain.
In these cases, contamination may come from any number of sources, including
failed septic systems, marinas or wildlife in or near the water.

"Municipalities have only so much money to spend on prevention.  It helps to
know where it will do the most good," said Dorworth.

For educators and concerned organizations, IISG and the E.coli Task Force
have created a series of posters that provide clear and concise information
about a range of beach and water quality issues, such as How does E.coli get
into the lake?, along with ideas to help protect the lake. They can be
accessed on the IISG Web site at http://www.iisgcp.org/beachwatch. To order
the set of 16 posters, call Irene Miles at 217-333-8055. Postcard-sized
copies of several of the series are also available.

IISG has also developed water quality fact sheets that can be ordered online
at http://www.iisgcp.org/pubs/wq/fsht.htm.


The Illinois-Indiana Sea Grant College Program is one of 30 National Sea
Grant College Programs.  Created by Congress in 1966, Sea Grant combines
university, government, business and industry expertise to address coastal
and Great Lakes needs.  Funding is provided by the National Oceanic
Atmospheric Administration (NOAA), U. S. Department of Commerce, Purdue
University at West Lafayette, Indiana, and the University of Illinois at

* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
glin-announce is hosted by the Great Lakes Information Network (GLIN):
To subscribe: http://www.glin.net/forms/glin-announce_form.html
To post a message: http://www.glin.net/forms/glin-announce_post.html
To search the archive: http://www.glin.net/lists/glin-announce/
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *