Ten Threats: Bacteria Hits the Beaches

  • Lake Michigan dunes with a power plant in the background. (Photo courtesy of EPA)

If you swim or play on the beaches around the Great Lakes, you’ve
probably heard about ‘beach closings.’ At best, the situation is an inconvenience.
At worst, it’s a serious health risk for some people. That’s because the
beaches are closed due to dangerous levels of bacteria in the water.
Beach closures are not all that new, but Shawn Allee reports… the
science behind them could change dramatically in the next few years:

Transcript

We’re continuing our series, Ten Threats to the Great Lakes. Our field guide through the series is Lester Graham. He says anyone who visits Great Lakes beach is familiar with one of the Ten Threats.


If you swim or play on the beaches around the Great Lakes, you’ve
probably heard about ‘beach closings.’ At best, the situation is an inconvenience.
At worst, it’s a serious health risk for some people. That’s because the
beaches are closed due to dangerous levels of bacteria in the water.
Beach closures are not all that new, but Shawn Allee reports… the
science behind them could change dramatically in the next few years:


(Sound of dog and beach)


During the summer, dogs and their owners usually play together in the
water along this Lake Michigan beach, but today, several dog owners
scowl from the sand while their dogs splash around.


“It’s e coli day … it’s a hardship.”


This beachgoer’s upset, and like she said, e coli’s to blame.


Park officials tested the water the previous day and found high levels of
the bacterium. Missing a little fun on the beach doesn’t sound like a big
deal, but there’s more at stake than recreation.


Cameron Davis is with the Alliance for the Great Lakes, a regional
advocacy group.


“Beaches are most peoples biggest, tightest connection to the Great
Lakes, so when beaches close, they really impact our quality of life in the
region.”


And ultimately, health is at stake too. For a long time, scientists tested
beach water for e coli because it’s associated with human feces. That is,
if e coli’s in the water, there’s a good chance sewage is there too, and
sewage can carry dangerous organisms – stuff that can cause hepatitis,
gastric diseases, and rashes.


Sewage can get into the Great Lakes after heavy rains. That’s because
some sewers and drains can’t keep up with the flow, and waste heads to
the lakes.


For a long time, scientists thought human feces was the only source of e
coli in Great Lakes water, but a puzzling phenomenon has them looking
for other causes, too. Experts say cities have been dumping less sewage
into the Great Lakes in recent years, but we’re seeing more e coli and
more beach closings.


Paul Bertram is a scientist with the U.S. Environmental Protection
Agency. He says, we’re closing more beaches because we’re testing
them more often.


“But I don’t think it’s because the Great Lakes are getting more polluted,
and more filled with pathogens, I think we’re just looking for it more.”


If we’re finding more e coli because we’re testing more often, we still
have a problem. We still need to know where the e coli’s coming from.
Bertram says there might be another culprit besides sewage.


“There is some evidence that it may in fact be coming from birds, flocks
of seagulls, things like that.”


But some researchers doubt sewage and bird droppings can account for
high e coli levels.


(Sound of research team)


A few researchers are sorting vials of water in a lab at the Lake Michigan
Ecological Research Station in Indiana.


Richard Whitman leads this research team. He says, in the past,
scientists could predict beach closings by looking out for certain events.
For example, they would take note of sewer overflows after heavy rains.
Whitman says researchers can’t rely on those triggers anymore.


“A large number, maybe even a majority of closures remain unexplained.
Today, we have closures and there’s no rainfall, may not even be
gulls, and we don’t know why the bacteria levels are high.”


Whitman has a hunch that e coli can grow in the wild, and doesn’t
always need human feces to thrive.


“This is my theory. E coli was here before we were. It has an ecology of
its own that we need understand and recognize.”


The idea’s pretty controversial. It runs against the prevailing theory that
e coli only grows in waste from warm-blooded animals, such as human
beings and gulls, but the idea’s also a kind of political bombshell.


If he’s right, it would mean our tests for e coli aren’t very accurate – they
don’t tell us whether there’s sewage around. After all, if e coli is nearly
everywhere, how can we assume it’s a sign of sewage?


“As a pollution indicator, you don’t want it to multiply. If it’s got an
ecology of its own, multiplying on its own, doing its own thing, then it’s
not a very good indicator.”


Whitman wants us to try other kinds of tests to find sewage. One idea is
to look for caffeine in the water. Caffeine’s definitely in sewage but it’s
not found naturally in the Great Lakes, but until we change our water
tests, Whitman will continue his work. He says we still need to know
how much e coli’s in nature and how much is there because of us.


Environmentalists want the government to keep a close watch on the new
science. They say we can’t let questions about the relationship between
e coli and sewage stop our effort to keep sewage and other waste out of
the Great Lakes.


For the GLRC, I’m Shawn Allee.

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