No traces of Asian carp found in Milwaukee waterways
No traces of Asian carp DNA have been found in water samples
collected from major Milwaukee waterways, according to the
University of Notre Dame researchers who did the sampling.
The researchers notified the Wisconsin Department of Natural
Resources of the results in a letter last week. The DNR provided
boats and boat operators to help collect the water samples from the
Milwaukee, Menomonee, and Kinnickinnic rivers and nearby creeks and
ponds in November 2010.
“The great news is that all samples were negative for the
presence of Asian carp DNA,” says Bob Wakeman, aquatic invasive
species coordinator for the Wisconsin Department of Natural
Wakeman says the results are also an important contribution to
the baseline information we’re gathering on aquatic invasive
species within the state.”
Last January, the Notre Dame researchers had identified for the
first time in Lake Michigan genetic material from Asian carp. The
DNA was found in water samples collected from Calumet Harbor on the
lake, near the Illinois-Indiana border, with a second DNA match
turning up in the Calumet River in Illinois, within a half-mile of
Those earlier findings raised concerns that the carp had found
its way beyond the barrier system built to prevent the fish from
entering the Great Lakes.
The new sampling was conducted and analyzed by the University of
Notre Dame. The U.S. Fish and Wildlife Service provided funding for
the sampling through the Great Lakes Restoration Initiative.
Mike Staggs, DNR’s fisheries director, says these new results
are great news, “but all the more reason to make sure we block
access from the Mississippi River now. Asian carp have the
potential to be a serious threat to our Great Lakes fisheries and
An estimated 235,000 anglers fish 3.7 million days every year
for fish in Wisconsin’s waters of Lake Michigan and Lake Superior,
Staggs says. They caught 766,000 fish in 2008, and generated an
economic impact of $419 million. Wisconsin’s Great Lakes waters
also support commercial fisheries.
There are three species of Asian carp that are considered
invasive and a threat to the Great Lakes — the bighead, silver and
black carp — because of their feeding and spawning capabilities.
Bighead carp are capable of consuming 20 percent of their own body
weight in food each day, and so compete with other fish and aquatic
organisms for food. Silver carp are smaller, but pose a greater
danger to recreational users because of their tendency to jump out
of the water when disturbed by boat motors. They can severely
impact fishing and recreation. They can spawn multiple times during
each season and quickly out-compete native species by disrupting
the food chain everywhere they go.
Asian carp were imported to the southern United States to help
keep aquaculture and wastewater treatment retention ponds clean,
Staggs says. Flooding in the 1990s allowed them to spread to the
Mississippi River basin and other large rivers. They have been
found occasionally in Wisconsin waters of the Mississippi River,
but are not established or abundant in them. Now, these invaders
are in the Chicago Sanitary and Ship Canal, built over a century
ago to artificially connect Lake Michigan to the Mississippi River