Letter to the Editor: Confidence in Asian Carp Containment Efforts

The Army Corps of Engineers, in collaboration with our federal, state, and local partners in the Asian Carp Regional Coordinating Committee, continues to pursue all actions needed to contain the Asian carp threat below the electric fish barrier in the Chicago Sanitary and Ship Canal (CSSC). Based on available evidence, we have high confidence that sustainable Asian carp populations are located well below the fish barrier, and that the barrier system itself is highly effective against the sizes of Asian carp that may be in its vicinity. Neither the Corps nor our partners are taking our success to date for granted, but are continuing to pursue additional information about Asian carp populations in the Illinois River system, as well as advancing monitoring efforts, scientific research, and improvements to the fish barrier system. To this end, we are continuously improving our knowledge of the complex variables at play and we will apply that improved knowledge, as it develops to ensure continued success.

The Corps has used available Congressional authorities in an aggressive fashion and has taken advantage of funding from multiple sources, including Corps of Engineer appropriations, American Recovery and Reinvestment Act funds, and Great Lakes Restoration Initiative funds to accelerate numerous initiatives. Our proactive efforts include construction of additional fish barriers, intense inter-agency monitoring, the use of telemetry and sonar to verify barrier system effectiveness, and fish- population reduction efforts.

The Corps has also undertaken research to develop a more precise understanding of how Asian carp respond to the fish barrier’s operating parameters. The latest extensive laboratory research results, released in March 2011, indicate that the barrier system is working as designed and the current settings are effective at repelling Asian carp of the sizes currently believed to be nearest the barrier location. The report does suggests that higher operating parameters than those currently in use may be necessary to immobilize all very small Asian carp, as small as 1.7 to 3.2 inches in length, should they approach the vicinity of the barrier system.

The Corps has expanded the use of ultrasonic telemetry to determine fish behavior near the electric fields. To date, ultrasonic transmitters have been implanted into over 100 fish (below the barrier, both Asian carp and surrogate species are tagged; above the barrier only surrogate species are tagged), with about another 100 fish to be tagged this spring and summer. Thirty-two stationary receivers collect tracking data from the tags, supplemented by mobile tracking to identify the locations of the tagged fish. We have over 1.2 million detections from the tagged fish that indicate none has crossed any of the electric barriers. The same data also indicates that common carp are able to navigate the Lockport, Brandon Road, and Dresden Island Lock and Dams.

Despite recovery of over 130,000 pounds of fish from a single stretch of waterway and over 3200 hours of intensive and focused fishing efforts by resource agencies in the last year, only a single Asian carp has been found above the fish barrier. The multi-agency team has concluded that any Asian carp that may be present above the fish barrier are in such low numbers are not positioned to develop a sustainable population. All objective evaluation of the evidence, science, and facts currently available support this conclusion.

Major General, Corps of Engineers