Mich. (AP) -- An adult Asian carp found in a Chicago waterway near Lake
Michigan this summer began its life far downstream and apparently got around
a series of electric barriers intended to keep the invasive species out of
the Great Lakes, officials said Friday.
Autopsy results and
a scientific analysis showed the silver carp, which was caught June 22, was
a 4-year-old male that originated in the Illinois/Middle Mississippi
watershed, according to the Asian Carp Regional Coordinating Committee, a
coalition of government agencies.
It could have
hatched anywhere along a roughly 200-mile (320-kilometer) stretch of the
Illinois River before migrating northwest, said Charlie Wooley, the Midwest
deputy regional director for the U.S. Fish and Wildlife Service. It spent
time in the Des Plaines River before finding its way to the Little Calumet
River just 9 miles (14 kilometers) from the lake, where a fisherman landed
The only way the
carp could have gotten there was to evade three barriers in the Chicago
Sanitary and Ship Canal some 37 miles (60 kilometers) from Lake Michigan,
Wooley said. But it’s unclear how that happened.
The barriers emit
powerful electric pulses designed to repel carp that get too close or knock
them out and possibly kill them if they don’t turn back.
An earlier study
raised the possibility that small fish could be pulled through the electric
field in the wake of passing barges and survive.
Yet scientists who
conducted a chemical analysis of the carp’s inner ear bones to determine
which waters it had been in concluded the fish had spent no more than a few
weeks to a few months in the stretch of river where it was found. It was
fully grown, measuring 28 inches (71 centimeters) long and weighing 8 pounds
“We’re pretty darn
confident a fish of this size would be incapacitated going through” the
barriers, Wooley said, adding, “We’re baffled and we just don’t know how it
Aside from the carp
swimming through, another possibility is someone moved it past the barriers
-- intentionally or otherwise, said Kevin Irons, aquatic nuisance species
program manager for the Illinois Department of Natural Resources. The fish
might have jumped onto a boat and been carried past the barriers, then
thrown out by an occupant who didn’t realize what type it was, he said.
The analysis was
conducted by experts with Southern Illinois University, the Fish and
Wildlife Service and the U.S. Geological Survey.
The fish was only
the second live Asian carp ever caught past the barriers; the other was in
2010. The find gave fresh ammunition to critics who question the
effectiveness of the government’s strategy for protecting the lakes. A
search of the area where it was captured turned up no others.
“It confirms what
we’ve known all along -- those electric barriers are not foolproof and
additional protections are needed,” said Molly Flanagan of the Alliance for
the Great Lakes, a Chicago-based environmental group.
that bighead and silver carp, both imported from Asia decades ago, could
out-compete native species for food if they become established in the Great
Lakes, where commercial and sport fishing are worth billions of dollars
groups and officials in some of the region’s states, including Michigan,
have called for separating the Great Lakes and Mississippi River watersheds
by installing dams or other physical barriers in the Chicago waterways.
industry leaders in Illinois and Indiana oppose that, saying it would
disrupt freight shipping on the busy waterway.
The U.S. Army Corps
of Engineers this month released a report calling for $275 million in
technological and structural upgrades at the Brandon Road Lock and Dam near
Joliet, Illinois, part of the aquatic chain that connects Lake Michigan to
the Asian carp-infested Mississippi River watershed.
Stabenow, a Michigan Democrat, said the examination of the silver carp
proved it had gone past Brandon Road during its upstream journey.
“Time is of the
essence to both implement a permanent solution and take immediate steps to
stop Asian carp from reaching our Great Lakes,” Stabenow said.
Wooley said the
discovery of the single carp past the barriers doesn’t mean they are
“It just shows
we’ve got to be constantly on our toes, sampling the system and learning
about the system to make sure the fish don’t get ahead of us,” he said.