Something to Carp About

IN 1963 THE U. S. FISH AND WILDLIFE SERVICE introduced a foreign fish species into some American waters as a means to control aquatic weeds instead of using chemicals. This fish is known as the Asian Carp and like many other introduced wildlife, it has led to more problems than it solved. (see “kudzoo” and “starling”, for example) The Mississippi River floods in the early 1990’s led to significant escapes, bringing large numbers of the weird fish into the entire Mississippi waterway.

carp a cleveland leader

The Cleveland Leader

One sub-species, the Bighead carp, has no stomach, so it feeds constantly, depriving the other fish of their food supply. With no natural predators, the carp effectively take over an entire river. There are now some areas of the Mississippi, Missouri and Platte Rivers where the carp are more than 95% of the fish population. But since they are mostly bone structure, they are basically inedible.

Another weird sub-species is the Silver carp. This is the fish that shows up on YouTube videos showing them flying into the air. As boats pass by, the motors agitate the fish and they jump out of the water, sometimes as high as 10 feet. The fish that weigh up to 50 lbs. can injure boaters and water skiers. Most areas of the Illinois River are now completely devoid of recreational boaters and water skiers.

A serious problem has arisen recently with the encroachment of the carp into the upper reaches of the Illinois River. The headwaters of the Illinois are connected to the Chicago Sanitary and Ship Canal which links the Mississippi waters with the Great Lakes via the Chicago River that runs into Lake Michigan. The Fish & Wildlife Service is genuinely worried that if the Asian carp make it into Lake Michigan, then there will be no stopping a population explosion that would effectively destroy all fishing in the entire Great Lakes system.

The carp are already into the canal, but they have been prevented from entering the lake by an electronic “curtain” set up near the northern end that prevents any fish from passing. Starting today, a massive fish kill program will be taking place in the canal as the F & W people begin dumping massive amounts of a toxin called rotenone that parlyzes their gills, but has no effect on plant life or humans.

The Illinois Department of Natural Resources will drop 2,300 gallons of rotenone into into a six-mile-long stretch of the canal. The fish kill is so large that rotenone’s manufacturer couldn’t supply enough of the poison. Illinois officials had to get donations from fish and wildlife officials in other states. A crew of 200 will work five days to execute the fish kill. Removing more than a quarter-million tons of dead fish will be a challenge in itself.

USA Today has an excellent article about the carp and this kill project HERE. It’s a little lengthy, but worth taking the time to read.

WFLD-TV has a video summary of the planned kill: