Program script for Tuesday, June 11, 2002
By Amber Rose Fonzen
An exotic fish is headed up the Mississippi River and
could get into the Great Lakes.
People imported Asian carp into the United States to
use them in fish farms to clean up algae. The hungry fish
clear algae out of aquaculture tanks like vacuum cleaners.
But about 10 years ago, the Asian carp got out of the
fish farms and into the Mississippi River. It might have
happened when the river banks overflowed into fish ponds.
But whatever the cause, the fish are loose. People in
the Mississippi River basin are trying to control them,
but the carp keep multiplying and spreading. In fact,
they're headed upstream and straight for the Great Lakes.
Jerry Rasmussen is a fisheries biologist for the U.S.
Fish and Wildlife Service. He's worried that the food
chain in the Great Lakes cannot support the huge appetite
of this foreign fish.
"The food supply is there, the temperature is
right and if they can get in there through a waterway
connection and an obvious waterway connection is the connecting
channels in the Chicago area that connect the Great Lakes
with the Illinois River . . . If there's anything I could
do to keep them out I would do it and do it right away."
A ship canal in Chicago connects Lake Michigan to the
Illinois River, and the river connects to the Mississippi.
That gives the Asian carp a straight shot into the Great
Lakes. Government officials have installed an electric
barrier in the Chicago canal to shock the carp and turn
them around. Rasmussen says other irritants might be added
to it for maximum carp aversion.
"They don't like noise. They don't like bubbles.
So maybe a combination of noise, bubbles and the right
amount of electricity could stop them dead in their tracks."
Rasmussen says it might take more than that to stop the
Asian carp -- even something as drastic as shutting down
the Chicago Ship Canal.
"It's almost pay me now or pay me later. Either
you put up the money now before the problem occurs or
you end up treating the problem after it's already there
along with all of the repercussions that come along with
big fish: Asian carp are threat to lakes" in the Detroit
Free Press, 11 April 2002
Carp Invasion of the Upper Mississippi River System",
report from U.S. Geological Survey Upper Midwest Environmental
from the U.S. Fish and Wildlife Service in pdf format