In the mid-20th century, wastewater plants started importing silver carp and bighead carp. They thought these fish would clean up the water and solve an ecological problem since they were good at consuming algae blooms. However, it became a much bigger problem.
Before 1900, the sewage from Chicago flowed down the river into Lake Michigan. Because the city’s drinking water was offshore, there was a fear that it could become contaminated and cause disease outbreaks. City officials decided to dam the river and reversed the flow so that the sewage and wastewater would move in the opposite direction away from Lake Michigan. They built the 28-mile-long Chicago Sanitary and Ship Canal to provide a passageway to Lake Michigan.
The Great Lakes has a $7 billion fishing industry and a $16 billion recreational boating industry. If the carp get through and enter the Great Lakes, these industries would collapse, and the results on the economy of this region would be disastrous.
The barrier of electricity at sites 2A and 2B is 2.3 volts per inch, and the border of electricity at site 1 is 6.0 volts per inch. Like an electric fence keeps dogs in someone’s yard or prevents outsiders from entering someone’s private farm, this underground electric fence keeps fish from swimming any farther.