Six-week search finds no Asian carp in Chicago-area rivers and canals
AP Environmental Writer
Traverse City, Mich. (AP) — An initial six-week mission to catch
and kill Asian carp lurking on the Great Lakes’ doorstep turned up
none of the despised fish, suggesting few if any have eluded an
electric barrier designed to block their path to Lake Michigan,
officials said recently.
Beginning in mid-February, teams of biologists and commercial
fishermen combed a network of Chicago-area rivers and canals where
Asian carp DNA has been detected in numerous spots over the past
year. They spread netting across large areas and used electric
stunning prods where they believed the carp were most likely to
gather, said Chris McCloud, spokesman for the Illinois Department
of Natural Resources.
The operation yielded more than 1,000 common carp, a similar
number of gizzard shad and a few other varieties but no silver or
bighead carp – natives of Asia that have infested sections of the
Mississippi and Illinois rivers plus the Chicago waterways south of
the electric barrier, some 25 miles from Lake Michigan.
“What this tell us is if they are present above the barrier,
they are in very low numbers as we’ve said before,” McCloud
The barrier’s effectiveness is a key issue in the debate over
whether to close shipping locks in the waterways to keep the
invasive carp from entering Lake Michigan, as sport fishing
interests and most states along the Great Lakes would like.
Notoriously prolific, Asian carp can grow as large as 4 feet
long and 100 pounds and eat up to 40 percent of their body weight
daily in plankton, the base of the lakes’ food chain. Scientists
say that if the species spreads across the lakes, it could damage
the $7 billion fishing industry.
Recreational boating also could suffer. Silver carp are known to
become startled by motors, leaping from the water and colliding
Illinois and the Obama administration oppose closing the locks,
siding with Chicago barge and tour boat companies who say doing so
would devastate their businesses. They contend the electric barrier
is performing well and closing the leak-prone locks wouldn’t be a
The U.S. Supreme Court last month refused for a second time
Michigan’s request to order the locks closed.
The sampling operation was conducted by the Illinois DNR, the
U.S. Fish and Wildlife Service and the U.S. Army Corps of
Engineers. Their crews set more than 5 miles of netting in the main
channels of the Chicago Sanitary and Ship Canal, the Des Plaines
River and other waterways, plus barge slips, marinas and other
likely carp hideouts.
Early on, the teams focused on areas where warm water was being
discharged from industrial operations, including power plants and
wastewater treatment plants. Fish tend to congregate near warmer
water during winter. As spring approached and ice receded, the
search area was broadened.
To make sure they were using effective techniques, the crews
also searched for Asian carp below the electric barrier. They
nabbed 36 silver carp and four bighead carp near Starved Rock Lock
and Dam, about 70 miles downstream.
Ashley Spratt, a spokeswoman for the fish and wildlife service,
acknowledged the failure to catch any Asian carp above the barrier
didn’t necessarily mean none were there.
“They are hard to catch and this is a big area we’re looking
at,” she said.
John Sellek, a spokesman for Michigan Attorney General Mike Cox,
said last week that although no Asian carp were found, Michigan
still wants the locks closed.
“What did they expect? (Illinois’) own court filings say they
are not likely to catch Asian carp using nets or electro-fishing,”
Biologists plan to continue searching over the next three months
as part of a $78.5 million Asian carp control strategy.
“Intensifying our sampling and monitoring efforts in high-risk
areas for Asian carp provides us with critical data on population
dynamics, potential range expansion and movement of the species,”
said Charlie Wooley, deputy regional director for the fish and