By Ms. Sarah Gross (USACE)February 1, 2013
Although the adult population front of the invasive Asian carp has remained around 55 miles from Lake Michigan since 2006, U.S. Army Corps of Engineers Great Lakes and Mississippi River Interbasin Study Program Manager Jack Drolet states that "active prevention projects are ongoing and effective, such as operation of the electric barriers in the Chicago Sanitary and Ship Canal and partnering with other members of the Asian Carp Regional Coordinating Committee to aggressively monitor the canal to determine location and abundance of fish."
Site preparation for permanent Barrier I is scheduled to begin in spring 2013. This barrier was authorized by Congress as an upgrade of the Demonstration Barrier, which began operating in 2002. The barriers deter the inter-basin passage of Asian carp and other swimming aquatic nuisance species via the Chicago Sanitary and Ship Canal through the use of pulsed direct current in the water from steel electrodes secured to the bottom of the canal that discourages fish from crossing.
These barriers are the largest of their kind in the world and are located on a highly-trafficked, commercially-navigable waterway, though they do not block the flow of water or the movement of vessels. Therefore, the canal continues to serve its intended purposes for wastewater and storm-water management and navigation.
"As novel as this technology is, lab and telemetry results show that it is an effective fish deterrent, and we will continue our rigor-ous interagency efforts to monitor the canal and work with our stakeholders to make any necessary adjustments to the operations. Barrier I is the culminating technology based on lessons learned from our other permanent Barriers IIA and IIB," said U.S. Army Corps of Engineers, Chicago District Deputy Commander Lt. Col. Jim Schreiner.
To date, individually coded transmitters have been surgically implanted into 201 fish, as far downstream as the Marseilles Pool. Stationary receivers collect tracking data, supplemented by monthly mobile tracking. There have been over 6 million detections from tagged fish with a 75 percent detection rate. No tagged fish have crossed any of the electric barriers in the upstream direction. USACE plans to deploy 32 receivers in spring 2013. Southern Illinois University, Carbondale and the U.S. Fish and Wildlife Service (USFWS) also have receivers in the waterway.
"Monitoring data are used to characterize and understand fish populations around the barrier," said USFWS Fish Biologist Sam Finney.
Dual-Frequency Identification Sonar (DIDSON) is another monitoring method used by USFWS. Each week during the monitoring season (generally May through October), this underwater acoustic camera captures around 80 10-minute recordings of fish behavior in and around the barriers. There are currently eight DIDSON devices in the barriers' region that are able to capture seven frames per second of video footage.
"For the Chicago Area Waterway System, alone, we participated in 194 hours or 774 runs of electrofishing for both random and fixed-site sampling in 2012, not to include additional agency efforts, commercial fishing or the rapid response actions that took place," said Kevin Irons, aquatic nuisance species program manager, Illinois Department of Natural Resources.
To put the vast amount of effort spent on monitoring approximately 70 miles of the CAWS into perspective, as part of another effort in 2012, the well-respected Long Term Resource Monitoring Program participated in 123 hours or 492 runs of only fixed-site electrofishing throughout the Upper Mississippi River System. This monitoring occurs in six reaches of the UMRS comprising of approximately 272 river miles from Minnesota to the open river below St. Louis Missouri and 78 miles of Illinois River. Moreover, this program monitors for all fish and not specific or rare species.
The ACRCC 2012 Monitoring and Rapid Response Plan (MRRP) initiates an extensive netting and fishing rapid response operation after three consecutive positive Asian carp environmental DNA (eDNA) samples are collected in a specific area. Of the over 30,000 fish sampled during all five rapid responses in 2012, no Asian carp were found.
"We continue to do a ton of work to better interpret Asian carp environmental DNA results that will inform future monitoring and analysis," said USACE eDNA Program Manager Dave Schulenberg.
Current eDNA work includes identifying potential sources for Asian carp DNA to enter the CAWS beyond a live fish, developing new genetic markers to aid researchers in their ability to estimate Asian carp populations and movement and increasing the efficiency of eDNA processing.
Visit asiancarp.us for a detailed interim summary report, as well as the complete 2012 monitoring plan and other inter-agency detection, surveillance and down-river removal efforts.