Testing complete on Bighead Asian Carp Found in Lake Calumet

Illinois Department of Natural Resources

August 5, 2010 

Chris McCloud 
(217) 785-0075

View Complete Test Report

Fish could have lived most of its adult life above Electric Barrier Defense System

CHICAGO – A six-year-old Bighead carp that was caught in the waters of Lake Calumet   just outside Lake Michigan in late June may have lived nearly its entire life in waters of Great Lakes origin according to tests and analysis conducted by Southern Illinois University Carbondale (SIUC).

The tests were conducted by the SIUC Fisheries and Illinois Aquaculture Center.

The tests looked at chemical markers in the inner ear bones, or otoliths, of the fish.  Otoliths incorporate chemicals into their structure that are unique to the environments in which they live.  They have been used in recent years to reconstruct the environmental history of individual fish or fish stocks.

“The inferences about the environmental history of this fish should be viewed as preliminary and inconclusive given the data limitations and assumptions. But it is very plausible that this fish originated in the Illinois River and then moved or was transported to Lake Calumet or Lake Michigan during the early portion of its life” said Dr. Jim Garvey, director of the SIUC Fisheries and Illinois Aquaculture Center.

The Bighead carp, which measured 34.6 inches and weighed nearly 20 pounds, remains the only Asian carp found above the electric barrier despite extensive sampling and search operations since June 22 throughout the Chicago Area Waterway System (CAWS).

“While this report does not have all the answers, it does suggest to us that the fish caught in Lake Calumet last month may have been put there by humans, perhaps  as a ritual cultural release or through bait bucket transfer.  It underscores the need for the public to be even more vigilant and educated about Asian carp and the importance of not furthering the spread of these invasive species,” said Illinois Department of Natural Resources Assistant Director John Rogner.

The Illinois Department of Natural Resources will continue to work with nearly 60 Chicago area bait shops in September to test for Asian carp DNA and educate bait shop owners on how to tell the difference between Asian carp minnows and other fish with similar characteristics that are commonly used as bait.

Sampling above the electric barriers also remains an important and continued effort in the Asian Carp Control Strategy Framework, which includes both short and long term actions to stop the migration of Asian carp into the Great Lakes.

Sampling and monitoring will continue at five fixed sampling stations throughout the Chicago Area Waterway System as detailed in the Asian Carp Regional Coordinating Committee (RCC) Sampling and Monitoring plan to search for Asian carp.

Barrier defense operations will also continue to remove silver or Bighead carp in downstate waters where the fish are known to be present.