A study commissioned by the Minnesota DNR has led the agency to recommend bubbles, lights, and sound as the best barrier to Asian carp on the Mississippi River.
The DNR hopes to keep the invasive fish from advancing beyond the Ford dam in St. Paul. The study found an electric barrier at the lock and dam could bring a public health risk and would likely be opposed by federal officials.
Consequently, the agency will recommend the Legislature fund the non-electric alternative, which involves underwater speakers and strobe lights. The cost of installing the system is estimated at $12 million to $19 million. The engineering firm that conducted the study concedes the technology is unproven and will not be 100 percent effective.
There are two varieties of Asian carp, bighead and silver. The carp are voracious eaters whose arrival in the Great Lakes or northern Minnesota would threaten native sport fish and the lucrative angling industry.