Jumping carp infest some Iowa waterways
Their big appetites deprive
other fish of food, and some people have been hurt after
being struck by them.
By Perry Beeman
Des Moines Register
Published July 3, 2005
Humongous jumping carp are living in Iowa and starving
other fish by eating too much.
The fish can be a hazard to humans as well. Boaters have
had teeth knocked out and ribs broken when struck by the
jumping fish on the Mississippi, Illinois and Missouri
There have been no reported injuries to Iowans, but boaters
on the Des Moines River downstream from Ottumwa have seen
silver carp - which can grow to 50 pounds - jump behind,
over or into their boats.
These intruders - which are native to China and were
imported to Arkansas fish ponds in the early 1970s - have
made themselves at home in the Mississippi, Missouri and
Illinois river systems. Ditto for Asian bighead carp,
which can weigh more than 50 pounds, but don't jump when
Iowa and several other states now are working on ways
to keep the fish from spreading into other waterways.
Scientists think the fish moved into the rivers during
floods or were purposely released after they proved unmarketable
for the fish farms.
State officials don't know specifically of any Iowans
hurt by the fish; however, a Peoria, Ill., woman was knocked
out by a carp on the Illinois River in 2003. She was riding
a personal watercraft and suffered a concussion, broken
nose and broken foot.
"We have thousands, maybe millions, of bighead and
silvers in our rivers," including several of the
major Mississippi tributaries, said Marion Conover, Iowa's
fisheries chief. Bighead carp outnumber channel catfish
in some stream stretches now.
The carp are filter feeders, which means they eat all
the plankton and other little stuff that all larval fish,
and some adults of some species, rely on for survival.
A hydroelectric plant at Keokuk, the Red Rock dam on
the Des Moines River, and small dams along the Mississippi
tributaries have helped slow the spread, but environmental
officials in the Midwest are looking for ways to stop
the fish from taking over other waterways.
Randy Moore, 36, of Prairie City has heard stories of
the carp knocking into people when they jumped, but said
he thought they were folklore. He knows firsthand - the
big carp are not.
Moore set a state record when he caught a 4-foot, 54-pound
bighead carp in the tailwater below the Red Rock dam while
fishing with two other men. It took him 45 minutes and
required help from all three fishermen to reel it in.
"It was a beast," Moore said. "It was
so big it actually busted the net."
Just before a storm Tuesday evening, Moore spotted what
he thinks was another giant carp in about the same place.
This time he saw it jump. He snagged something strong
and shortly thereafter the fish leapt about a foot and
a half out of the water and threw the hook back at him.
"As soon as I set the hook in, I knew I had something
big on," Moore said.
Some people have spread nets across their fishing boats
to keep the startled fish out. Chicago installed a system
in the Illinois River that sends a small electrical current
into the water to deter the carp.
Now, Iowa and other Midwestern states, especially Minnesota,
are pushing for federal money to install another type
of fish barrier - one that uses sounds that ride along
a curtain of bubbles to discourage the fish from moving
upstream. Great Lakes states are fighting hard to keep
the unwelcome silver and bighead carp out of their prized
Although no one knows if the carp will boom to numbers
that will significantly harm the native species such as
paddlefish and lake sturgeon, the U.S. Geological Survey
recently concluded there is a moderate to serious risk
of that happening.
The fish barriers can affect other species as well, which
makes efforts tricky. The U.S. Army Corps of Engineers
has planned fish passages at locks and dams that are set
to be reconstructed, to allow game fish easier access
to northern waters. Putting in fish barriers could work
against that goal.
Mark Cornish, a fisheries biologist with the Army Corps
of Engineers, said researchers have found the sound-and-bubble
systems can be tuned to scare the carp more than some
other species. The systems can cost about $15 million
each. They have been eyed for a series of locks and dams
downriver from Minnesota, especially the ones at Dubuque,
Davenport and Keokuk.
Bighead carp are found in large numbers as far north
as Muscatine; some have been found as far upstream as
Lake Pepin, Minn. Silver carp have been found in the Mississippi
River south of Keokuk and in the Des Moines River below
Cornish said it is unclear when Congress will consider
proposals to build the barriers. Minnesota lawmakers are
pushing for an appropriation in the next budget.
Register staff writer Kate Slusark
contributed to this article.