droppings top source of beach bacteria, study finds
By Michael Hawthorne
Those pesky seagulls begging for french fries and other
handouts along the shores of Lake Michigan are also responsible
for the high bacteria levels that are closing beaches.
In a study to be released Monday, Lake County officials
used DNA to identify seagull droppings as the top source
of E. coli bacteria in water samples collected last summer.
Human waste, most likely from sewage spills, came in second.
The study is the latest attempt to grapple with a high
number of swimming bans every summer. There were 178 beach
closings in Lake County last year. Chicago had 130.
Seagulls, lured by abundant food and attractive nesting
grounds, are increasingly common at beaches along the
Great Lakes. Many have become so addicted to human handouts
that they no longer are afraid of people. Some birds are
so aggressive that throwing them a fry or a piece of bread
is the only way to get rid of them--for a moment.
Reducing litter, in particular food and food packaging,
is considered one of the best ways to keep beaches clean.
But it's not the only solution. A panel of federal, state
and local officials that reviewed the study said more
also needs to be done to eliminate sewage spills into
"It's obviously more than the birds," said
state Sen. Susan Garrett (D-Lake Forest), who secured
the funding for the $30,000 study.
In July, power failures at pumping stations in Lake Bluff
and Lake Forest allowed more than 350,000 gallons of raw
sewage to spill into the lake. Human waste also occasionally
escapes treatment when heavy rains overwhelm the region's
aging sewers, or when sewage seeps out from leaking pipes.
Officials from the North Shore Sanitary District welcomed
the new study because it confirmed their long-standing
belief that sewage isn't the only cause of beach closures.
"We know more needs to be done," said Brian
Jensen, the district's general manager. "But this
study suggests we need a more comprehensive effort to
get these bacteria counts down."
To conduct the study, volunteers and local officials
scooped up bird droppings and pried open sewer covers
to sample raw sewage. They collected water from shallow
shore areas, where disease-causing E. coli bacteria typically
The results are similar to another study conducted last
year by a researcher from Purdue University's Calumet
campus in Hammond. At the time, Garrett and others questioned
the researcher's conclusion that seagulls were responsible
for unacceptably high E. coli levels in Lake Michigan.
Officials who reviewed the latest study are recommending
that all Lake County beaches have covered garbage cans
that are emptied at least twice a day. They also want
more study of beach grooming practices that could reduce
levels of bacteria that thrive in warm, wet sand.
To limit human sources of bacteria, local sewers should
be inspected for illegal discharges, the group said.
"The reality is we have a number of known sources
of bacteria that we can do something about," said
Joel Brammeier, manager of habitat programs at the Lake
Researchers are working on methods to alert the public
more quickly about water contamination. Current methods
force health officials to wait a day before learning the
In an attempt to predict when bacteria levels will be
high, officials plan to install equipment this summer
that will monitor wind, sunlight, rainfall and temperature
at Lake Forest Beach and the South Beach at Illinois Beach
State Park. A similar system tested at Chicago's 63rd
Street Beach four years ago predicted unacceptable E.
coli levels 86 percent of the time.
"We still have a lot of work to do," said Jack
Darin, director of Illinois' Sierra Club chapter. "It's
sad when we have to think twice about having a fun day
at the beach."