Waterways Update:Temporary Closure of the Thomas O’Brien Lock Scheduled May 20 to May 27, 2010.


The U.S. Coast Guard command responsible for the Illinois River and Chicago Port region of Lake Michigan, in conjunction with the Asian Carp Coordinating Committee.


The Thomas O’Brien Lock will be temporarily closed May 20 through May 27 for initial Asian carp suppression activity on the Little Calumet River below the Thomas O’Brien Lock and Control works. 


The Asian Carp Coordinating Committee and the Illinois Department of Natural Resources are conducting investigations to detect the potential presence of Asian carp and other aquatic nuisance species north of the fish barrier. They will be applying the commonly used piscicide rotenone in an effort to determine whether Asian carp are present in the tested area. Fishing nets will also be deployed across the channel for extended periods of time to collect fish killed during the testing.  The deployment of these nets is a primary reason for closure to navigation.


The U.S. Coast Guard has established a temporary safety zone from the Brandon Road Lock and Dam on the Illinois River near Joliet to Lake Michigan.

The purpose of the safety zone is to allow for modified operations on the river resulting from Asian carp suppression activity.

The temporary closure is being enforced so that the U.S. Coast Guard is able to take targeted action to protect vessels and people from hazards associated with and federal and state efforts to control the spread of Asian carp.


Is this closure permanent?

No, this closure is being conducted as a temporary measure only and does not indicate a need for long-term or permanent closure.

What does it mean if Asian carp are found? Does this warrant cause for alarm?

The presence of Asian carp alone is not cause for alarm. The objective of control measures is to prevent Asian carp from establishing a self-sustaining population in the Great Lakes.  Isolated instances of carp north of control barriers does not indicate the presence of a self-sustaining population.

Does finding Asian carp mean the barriers have failed?

No. All evidence indicates that existing barriers are working successfully.  According to the documents published by the U.S. Fish and Wildlife Service, there are 21 pathways through which Asian carp could have bypassed the barriers or otherwise introduced north of the barrier.

If the barriers are working then why might they find Asian Carp?

Asian carp and other species can be moved from one location to another through a number of paths, including flooding or being transported by human actions.   Examples include accidental and deliberate unauthorized releases by individuals, incidental inclusion of Asian carps in domestic shipments of food fishes and stocking of triploid into non-aquaculture waters for biological control. This is why other alternative measures to prevent Asian carp, including educational activities, additional regulatory control, and additional river barriers should be explored before permanent lock closure is considered.

(February 22, 2008, “Columbia River Basin Asian Carps Risk Evaluation,” Aitkin, J. Keven, Western Washington Fish and Wildlife Office, et al.)

If Asian carp get into Lake Michigan will they devastate the lake?

No, there is no evidence that Asian carp can successfully establish a self-sustaining population in Lake Michigan as they are unable to reproduce without long stretches of moving water found in rivers.  Additionally, the southern portions of Lake Michigan contain limited levels of plankton, the carp’s primary food source.  This aquatic “desert” is likely to further constrain any carp that were to reach the lake.

(August 31, 2008, “Evaluating Asian Carp Colonization Potential and Impact in the Great Lakes”, Illinois-Indiana Sea Grant)

What is prompting this temporary closure?

The Army Corps of Engineers is relying primarily on “preliminary” findings based on a questionable testing method known as eDNA to justify the lock closure. Closing the locks based primarily on eDNA is unwarranted.

The Army Corps of Engineers own Major General John Peabody pointed out in a recent congressional hearing that the  eDNA Detection System has not yet undergone a complete scientific independent peer review, and as such, any evidence based on eDNA, that the electronic barrier has been breached is ‘speculative.’”

(February 9, 2010, “Statement of Major General John Peabody, USACE”, Subcommittee on Water Resources and Development, Committee on TransNportation and Infrastructure, U.S. House of Representatives)

Does the research provided by eDNA mean that Asian carp are present?

The presence of genetic material above the barriers is preliminary and does not indicate the presence of actual carp.

What does the temporary one week of closure mean for
the economy?

On an average week this spring, the locks transported 180,000 tons of materials. That’s the equivalent of more than 6,000 semi-truck loads of material rerouted, delayed, or often times unable to be delivered – a convoy that would stretch from Chicago all the way to Milwaukee.  Disrupting the flow of barges would have a negative effect on the economy.

The Chicago and O’Brien locks move 7,289,428 tons of commodities annually.  One study by DePaul University found that the economic impact to the Chicago region alone is over $582 million in the first year and reaches $4.7 billion over the next 20 years if shipping locks were to close permanently.

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