Print PageThere are many species that are grouped and called Asian Carp, which are in the minnow family Cyprindae. The two species of Asian Carp that are currently considered a threat to the Great Lakes are the bighead and silver. Asian carp were originally imported to the southern United States in the 1970s to help aquaculture and wastewater treatment facilities keep retention ponds clean. The carp have escaped the farms and migrated up the Mississippi River system. They now threaten to enter the Great Lakes through the man made canal connecting the Great Lakes to the Mississippi River water shed. The carp displace native species of fish by filter feeding and removing the bottom of the food chain for indigenous species.
In 2002, the U.S. Army Corps of Engineers completed an electric fish barrier in the Chicago Sanitary and Ship Canal (CSSC), the only aquatic link between the Great Lakes and the Mississippi River drainage basins. The barrier project consists of two distinct parts: the demonstration barrier (Barrier I) and Barrier II. Like Barrier I, Barrier II is also a pulsed DC barrier, however it is located 800 to 1,300 feet downstream from Barrier I. The electric barrier consists of a series of electrodes placed on the bottom, and across the entire width, of the canal. Electric current passing between the electrodes, via the water medium, produces an electric field with electric field lines which run parallel to water flow. When fish are within the field, they become part of the electrical circuit with some of the current flowing through their body. The electric current passing through fish can evoke reactions ranging from a slight twitch to full paralysis, depending on the current level and shock duration they receive.
The U.S. Army Corps of Engineers, Engineer Research and Development Center, Construction Engineer Research Lab (ERDC-CERL) has conducted electrical field mapping on the fish barrier since 2005. During field mapping , a series of electrodes are placed in the water and towed over the fish barrier while continuously collecting data. These tests determine the strength and extent of the electrical field in the water.
Results/Conclusions
The Electrical Field Measurement will enable the COE and the Coast Guard to define the regions of non-hazardous fields in the water which can then be used to develop the RNA (Regulated Navigation Area) for safe passage over the barriers.
