The Illinois Department of Natural Resources and the U.S. Fish and Wildlife Service are searching for heat-seeking Asian carp.
Weather permitting, biologists will begin sampling in Chicago-area rivers and canals Wednesday for silver or bighead Asian carp that have made it past an electric fish barrier system.
Crews will focus on areas where warm water from industrial operations enters the waterways.
Fish tend to congregate near the warmer water in the winter as temperatures drop.
The barrier system is designed to keep carp out of the Great Lakes, where officials fear they could disrupt the food chain by starving out other fish.
While DNA samples suggest carp have breached the barrier, no physical fish has been found.
Distributed via Chicago Press Release Services