DNR launches attack on Asian carp invasion with bubbles
Minnesota’s Department of Natural Resources (DNR) will launch an all-out assault on the Asian carp by using bubbles and lights. That’s right, bubbles and lights.
The announcement was made Jan. 3 by the natural resources agency following an evaluation of viable options that might be effective in deterring the pesky bottom-feeding fish from invading waterways north of the Twin Cities.
“The goal is to prevent the fish from using the lock chamber to gain access to the upper reaches of the (Mississippi) river, which connects to other rivers and lakes,” the DNR report states.
An electric barrier inserted into the water would be the most effective technology for deterring the carp, but Barr Engineering Co., which was hired to find options for limiting the movement of carp into northern waterways, concluded that it is “not a feasible option due to significant public safety risks and corrosion to metal components of the lock.”
Wait a minute — is this going to amount to another failure on the part of the DNR to take the most effective route to keeping an invasive species out of our rivers and lakes? If one recalls the department was less than successful in its assault on millfoil and zebra mussels.
“A safer and less damaging alternative would involve a barrier using sound, air bubbles and lights,” the DNR reported. “Together, these technologies will deter fish and pose lower risks, but may not be as effective as electricity. The sound, air bubble and light barrier would be considered experimental because such barrier has never been tested in an environment similar to a lock chamber.”
So what’s this less than effective war on the Asian carp going to cost the taxpayers of Minnesota? Estimated costs of constructing the system is $12 million, but could go as high as $19 million. Annual operating and maintenance costs could be as much as $250,000.
How serious is this problem? The fish are capable of eating 5 to 20 percent of their body weight each day. Asian carp feed on algae and other microscopic organisms, often outcompeting for food with native fish. Scientists believe the fish could severely disrupt the aquatic ecosystems of Minnesota waters.
If this barrier system fails, it could be disastrous for the waterways in the Brainerd lakes area.