Giant Fish Invasion Spurs Drastic Measure

In this Thursday, Jan. 5, 2006 file photo, a bighead carp, front, a species of the Asian carp, swims in an exhibit at Chicago's Shedd Aquarium. Illinois environmental officials will dump a toxic chemical into a nearly 6-mile stretch of the Chicago Sanitary and Ship Canal Wednesday, Dec. 2, 2009 to keep the voracious Asian carp from entering the Great Lakes while an electrical barrier is turned off for maintenance.
AP Photo/M. Spencer Green, File

The Asian carp are coming and they seem unstoppable.

The 40- to 80-pound leviathan consumes 40 percent of its weight every day and is now a short swim from Lake Michigan. It spawns three times a year and has no known predators.

It devours the plankton and algae vital to other fish including the perch and salmon of the Great Lakes - threatening a $7 billion fishing industry, CBS News correspondent Dean Reynolds reports.

"Once they're here, there's no stopping them," said Joel Brammeier of the Alliance for the Great Lakes.

The carp's journey began in the 1970s when it was imported from China to clean southern fish hatcheries of algae.

But floods in the 1990s swept them into the Mississippi and its tributaries including the Illinois and the shipping canal that connects that river to Lake Michigan.

Their signature jumping style has gotten lots of grins on YouTube.

But Colonel Vincent Quarles of the Army Corps of Engineers isn't laughing.

"We have positive results from environmental DNA (that the carp is) one mile from this location downstream," Quarles told Reynolds.

Quarles mans an $10 million effort to stop the carp in the canal with two underwater electrical barriers - but with mixed results.

The Asian carp's progress has been inexorable and anything man has done to deter it has at most only delayed it.

Now the next step: temporarily poisoning the canal to kill the carp.

These fish will have to be sacrificed, it's reasoned, so the Great Lakes can survive.

(AP Photo/M. Spencer Green)
At left: Employees of the United States Environmental Protection Agency and the Illinois Department of Natural Resources take part in a electronic fish salvage operation of game fish in the Chicago Sanitary and Ship Canal Wednesday, Dec. 2, 2009 in Romeoville, Ill. before a toxic chemical is to be dumped on a nearly 6-mile stretch of the canal as part of state and federal efforts to keep the voracious and invasive Asian carp from reaching the Great Lakes.
  • Dean Reynolds
    Dean Reynolds

    Dean Reynolds is a CBS News National Correspondent based in Chicago.