Tuesday, August 10, 2010

Carp Above Barrier Maybe Put There By Humans

Aug 5: A six-year-old Bighead carp that was caught in the waters of Lake Calumet just outside Lake Michigan, and beyond the electronic barrier, 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. Illinois Department of Natural Resources Assistant Director John Rogner said, "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." 

    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. Dr. Jim Garvey, director of the SIUC Fisheries and Illinois Aquaculture Center said, "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."

    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). 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.

    Access a release from the Asian Carp Control website and link to the complete report (click here). Access the Asian Carp Control website for more information (click here).

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