Crews step up beach testing efforts
By John Myers
Duluth News Tribune
Published May 1, 2005
Crews will wade into Lake Superior and the Twin Ports
harbor starting Monday and probably will find high bacteria
levels. For the third consecutive summer, some beaches
almost certainly will be posted unsafe for humans.
Because some types of bacteria are more dangerous to
people than others, there will be a new effort this year,
using DNA technology, to determine specifically what's
in the water.
If the bacteria originate from birds, for example, it's
unlikely to cause as many human diseases. But if it's
from people, considered the most serious, the research
might help identify the source so it can be shut off.
"We know now that a lot of it (bacteria) in Lake
Superior is avian... but some of it is human, too,"
said Greg Kleinheinz, microbiologist and professor at
the University of Wisconsin at Oshkosh. His crews are
studying South Shore beaches.
WARNINGS A SURPRISE
The federally funded Great Lakes testing program began
in 2003 as interest increased in the rising rate of bacteria-related
beach closures. The particles, if swallowed, can make
people sick. The bacteria also can cause skin and eye
Since the program started, many people have been alarmed
that several beaches on Lake Superior and especially in
the Twin Ports harbor have tested positive for bacteria
levels that exceed federal safety standards. Some harbor
beaches in Duluth, on the bay side of Park Point, have
been posted as unsafe much of the past two summers.
There are some patterns when high bacteria levels have
been found, including windy days, when bacteria in the
sediment may be churned up, and days after heavy rains,
when dog feces and other matter on land is washed into
In some areas, heavy concentrations of waterfowl -- gulls,
ducks or geese -- have been noticed. A few cases may have
been related to sewer overflows or raw sewage illegally
funneled into the storm-sewer system or leaking from septic
It's becoming more clear that there probably isn't just
one cause of bacteria outbreaks on local beaches and that
solving the problem will take a multitude of efforts,
Even tracking the DNA from various bacteria has proven
difficult because there has been no historic Department
of Natural Resources library for possible sources, including
all the birds and animals that live near the lake.
In some cases, solutions have been simple. On Lake Michigan
in Wisconsin's Oneida County, officials strung fishing
line along the beach each evening, effectively keeping
gulls and geese from coming onto shore and defecating.
That simple move cut beach closures at the site from 24
one year to one the next.
For other areas, it will take more research, more money
and hard work to stop the source -- if it's possible at
"It's frustrating to us, and I'm sure to the public,
because we can't take one sample and say we found the
culprit," Kleinheinz said. "This isn't 'Beachfront
CSI.' It's not that simple."
Two Seagrant-funded studies by University of Minnesota-Duluth
researcher Randall Hicks are looking at harbor bacteria
using DNA testing. The first study, now in its second
year, is looking at whether E. coli bacteria may be able
to reproduce and thrive in the sediment or other parts
of the harbor -- without a host animal.
The second study is trying to determine whether Duluth
sewage flow elevates E. coli levels, as opposed to animal
and bird contributions.
Hicks' 2003 study on North Shore streams found that humans
were just a small contributor of the bacteria in those
waters, noting that birds and wildlife were much larger
contributors of E. coli.
"It becomes a risk issue at that point... Some diseases
can cross species barriers. Certainly, we're going to
be more concerned if all of the indicator bacteria were
turning up as human, though, and that hasn't been the
case," Hicks said.
WORST NEAR SHORE
On the Wisconsin side, Kleinheinz's crews from UW Oshkosh
have been testing in Ashland, Bayfield and Iron counties,
where they've found rural beaches are much different than
Rain plays less of a role in raising bacteria levels
in remote areas because there's little or no stormwater
runoff to carry sewage overflow or dog feces into the
lake from parking lots and streets -- a key problem in
Kleinheinz also is looking at how bacteria levels change
throughout the year. Checking through the ice in midwinter,
researchers didn't find any bacteria at beaches. But early
results seem to show bacteria levels slowly build throughout
summer, with occasional spikes.
"It seems to slowly build up as the season goes
on," he said, as new bacteria flow into the water
faster than the old bacteria die off.
The problem also seems to be isolated to very near the
shoreline. Samples taken in a foot of water show high
bacteria levels, while those taken a few feet farther
from shore at the same beach usually don't show a problem.
Still, the bacteria issue should be taken seriously.
In 2002, 69 people became seriously ill after swimming
in Nicolet Bay Beach in Wisconsin's Door County. Had the
beach testing program been in place then, warning signs
may have been up, and many of those people may not have
The good news so far, Kleinheinz said, is that even where
high levels of E. coli have been found on South Shore
beaches, no disease-causing pathogens have been found.
"If you see a sign, don't go in," he said.
Although there may not be any disease-causing pathogens
present, "Why take the chance?
"If there's no sign up, jump in," he said.
"Lake Superior is still a very clean lake. If you
can tolerate the cold water."