DNR: New Asian carp deterrent is feasibleA new report by the Minnesota Department of Natural Resources (DNR) has concluded that an Asian carp barrier using sound, bubbles and lights would be the most viable option to deter invasive fish from moving past Lock and Dam #1 in Minneapolis.
A new report by the Minnesota Department of Natural Resources (DNR) has concluded that an Asian carp barrier using sound, bubbles and lights would be the most viable option to deter invasive fish from moving past Lock and Dam #1 in Minneapolis.
The chief advantage of a lock barrier is that it does not need to block fish passage across the entire river, but to deflect fish away from the smaller opening at the lock, which will prevent fish from gaining access to the upper reaches of the river.
The DNR recently contracted with Barr Engineering Co. to evaluate options for an Asian carp deterrent barrier on the Mississippi River.
While an electric barrier inserted into the water would be the most effective technology for carp deterrence, the Barr report concluded it is not a feasible option due to significant public safety risks and corrosion to metal components of the lock.
The sound, air bubble and light barrier would be considered experimental because such a barrier has never been tested in an environment similar to a lock chamber.
The estimated construction cost is $12 million, though the cost could be as high as $19 million. The estimated annual operation and maintenance cost is up to $250,000.
The Minnesota Legislature approved a $7.5 million appropriation from the Outdoor Heritage Fund to design and construct Asian carp barriers, of which $5.6 million is allocated to design and construct the barrier at Lock and Dam #1.
Asian carp are capable of eating 5 to 20 percent of their body weight each day. They feed on algae and other microscopic organism, often outcompeting for food with native fish. In other states, Asian carp have become up to 80 percent of the fish biomass in rivers, displacing numerous other game and non-game species.