As you read this, silver carp — the invasive fish that can obliterate game species such as walleyes, and whose missile-like acrobatics have smacked boaters in the face from Iowa to Kentucky — are jumping in unprecedented numbers below Lock and Dam 5 on the Mississippi, 10 miles north of Winona.
While invasive carp swim upstream, the Minnesota DNR forms a committee
Barrier proposal to stop jumping silver carp is stopped in the Legislature by the DNR.
June 2, 2023 at 12:44AM
The carp likely are preparing to spawn, and some have been spotted catapulting in the lock itself, indicating that at least a few have moved farther upstream.
The carp's presence — the second large pod at the dam in recent months — underscores the high stakes, and some would say slow-motion, approach the Department of Natural Resources (DNR) has taken to preventing invasive carp from infesting the Upper Mississippi, the Minnesota and the St. Croix rivers and their tributaries.
An effort spearheaded by the conservation group Friends of the Mississippi River, joined by the angling group MN-FISH and others to establish a special deterrent system, or barrier, at Lock and Dam 5 intended to stop most invasive carp from establishing breeding populations upriver, was killed by the DNR in the most recent legislative session.
The presence of silver carp in the Mississippi and the threat they pose to Minnesota game fish as well as lake and river recreation has been apparent since at least 2011, when the DNR developed its first Invasive Carp Action Plan.
"Explore modifying Lock and Dams 5 and 8 to improve capabilities to deter invasive carp,'' was one proposal included in the plan.
Leading the DNR effort at the Legislature to deep-six the barrier idea was assistant commissioner Bob Meier, who told key legislators the project would be plagued by cost overruns and become "another Southwest Light Rail.''
Reached Wednesday, Meier said, "Neither Wisconsin nor the federal government has done anything (about the carp), and they have more to lose than we do,'' adding, "Everyone wants the DNR to do something but no one wants to give the DNR any money.''
In fact, flush with a $17.5 billion surplus, the Legislature in the recent session awarded the DNR $308 million in new operating money for the next two years, and another $117 million from the surplus.
Variously projected to cost between $12 million and $17 million, the Lock and Dam 5 deterrent system proposal was based in part on a report by Barr Engineering, a frequent government contractor.
Barr's study complements peer-reviewed research conducted by Peter Sorensen, a University of Minnesota professor and carp expert, who says the barrier, in concert with removal and other efforts, could stop up to 98% of silver carp from breaching the dam.
The barrier, essentially a series of bubbles, sounds and lights, is made by a British company and is already in use in Kentucky, where studies in the first summer of testing showed that of 254 tagged silver carp, 57 crossed the barrier when it was turned off, while only four crossed it while on. Separately, researchers counted 3,181 times silver carp approached the barrier when it was off, but only 612 times when it was on.
The Minnesota deterrent system, as envisioned, would be operated about half the year or less, and could be managed by the state or by the manufacturer. The Kentucky barrier is managed via the internet from Britain.
DNR researchers for years have studied invasive carp in the Mississippi and have also attempted to capture and kill carp when possible. Agency experts also are trying to understand the river's native fish and how a barrier might affect their movements.
"We're very actively monitoring both invasive carp and native fish in the Mississippi,'' said DNR fisheries chief Brad Parsons. "We have hundreds of fish tagged to determine where they're moving.''
Similarly, Sorensen, using Legislative-Citizen Commission on Minnesota Resources (LCCMR) funding, for three years has studied fish passage at Lock and Dam 5, and has yet to see a fish move upriver except through the lock.
"That's why I believe a deterrent system placed in the lock will be highly effective,'' Sorensen said.
Those findings likely will be among a boatload of information considered by a DNR committee now being formed that will further study the state's invasive carp problem.
That effort, in government speak, is called "structured decision making,'' and carries a price tag of about $75,000. The idea is to let various stakeholders weigh in on invasive carp and by the end of the year come up with — if not a solution or proposal — at least a report.
Critical now is how the DNR chooses to interpret legislative language in the recent session that awarded the agency $1.72 million "to prevent and manage invasive carp.'' Included is up to $325,000 "which may be used to study the Mississippi River Lock Dam 5 spillway and provide preliminary design to optimize management to reduce invasive carp passage."
If the $325k is spent for that study, which is important, and another $300,000 from the $1.72 million is appropriated for a 50% barrier design and $100,000 is allotted for research to study the practicality of building an elevator to accommodate native fish migrations at the dam, the money will be well spent.
If instead the DNR directs all of the $1.72 million for other uses, the barrier could be set back years, and possibly killed.
"The barrier is the best option we have and it will work, especially when used with the DNR's removal and other efforts,'' Sorensen said. "That's not the fundamental question. The fundamental question is how much we care about Minnesota's resources.''
None of the boat’s occupants, two adults and two juveniles, were wearing life jackets, officials said.
