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UPDATE: Six-inch silver carp found in Starved Rock Pool, Illinois River

September 11, 2015

Contact:
Chris Young, Communications Director, Illinois Department of Natural Resources
(217) 557-1240 or chris.young@illinois.gov

Note: For an updated map, please check out our post from October 15, 2015.

As part of a comprehensive monitoring plan for assessing location and populations of Asian carp on the Illinois Waterway, crews have detected silver carp less than 6-inches in length in the Starved Rock Pool of the Illinois River, just a few miles downstream from Marseilles Lock and Dam near Ottawa, Illinois. Complete details of the 2015 Monitoring and Response Plan (Plan) for Asian carp in the Illinois River and Chicago Area Waterway System (CAWS) can be found online at www.asiancarp.us.

In April 2015, fish less than 6-inches were found as far upstream as Peru, Illinois.  These fish were likely spawned in 2014.  Focused monitoring through June 2015 did not detect any of these small fish in the Starved Rock, Marseilles, or Dresden Island Pools of the Illinois River, despite historically high sampling rates.  From July 2015 to early September (Sept. 7, 2015), 99 silver carp less than 6-inches have been collected, all within the Starved Rock Pool.

Monitoring for young-of-year Asian carp in the Illinois River, Des Plaines River, and the CAWS takes place through sampling identified in the Plan by the Illinois Department of Natural Resources (IDNR), U.S. Fish and Wildlife Service (USFWS), U.S. Army Corps of Engineers (USACE), and research organizations from throughout the state.  Most notably, USFWS targeted these smaller fish with standard and experimental gears to increase detection of these sizes of Asian carp, concentrating on the historical locations and identifying any upstream movement.  This sampling targets a segment of the Asian carp population typically missed with adult sampling gears and provides information to help determine where Asian carp are successfully recruiting young.

 

Several conventional and experimental gears were deployed to locate smaller fish throughout the Illinois River, and inform the Asian Carp Regional Coordinating Committee (ACRCC) about small Asian carp occurrence and movement upstream.  Spawning of Asian carp in both 2014 and 2015 has been noted with high success in the lower Illinois River by these monitoring efforts, with small fish detected below Henry, Illinois in both years. 

“This information allows us to update our risk map and show that small fish have now been detected within 91 miles of Lake Michigan,” said Kevin Irons, IDNR Aquatic Nuisance Species Program Manager.  “Efforts to detect these fish farther upstream are ongoing and to date have not resulted in the capture of any small silver carp upstream of Starved Rock Pool.”

Other ongoing efforts by the IDNR include removal of 3.5 million pounds of adult Asian carp by contracted commercial fishing crews, telemetry studies identifying the movement of Asian carp throughout the Illinois River, and assessments of Asian carp populations.  Hydroacoustic assessments have documented reduction in populations of Asian carp within the river at all locations, with consecutive and significant declines in successive years (2013-2014) near the leading edge of the Asian carp population (Dresden Island Pool). 

Since 2001, USACE has operated an electric dispersal barrier system in the Chicago Sanitary and Ship Canal near Romeoville that has proved a significant deterrent for fish movement.  No silver or bighead carp of any size has been observed or captured near this barrier since one bighead was taken in the Lockport Pool below the barrier in 2009.  The closest adult Asian carp found in the Illinois River are approximately 55 miles from Lake Michigan, and no small Asian carp have been observed closer than 91 miles from Lake Michigan.  The overall leading edge of the Asian carp population in the Illinois Waterway has not changed since 2006.

As of September 2015, small Asian carp were found in the Starved Rock Pool of the Illinois Waterway. The location is 54 miles downstream from the electric dispersal barriers. Small Asian carp are now 91 miles away from Lake Michigan. This marks a 52 mile upstream increase in where small Asian carp were found in 2014.
As of September 2015, small Asian carp were found in the Starved Rock Pool of the Illinois Waterway. The location is 54 miles downstream from the electric dispersal barriers. Small Asian carp are now 91 miles away from Lake Michigan. This marks a 52 mile upstream increase in where small Asian carp were found in 2014.