A [scientifically] proven solution

How can we stop invasive carp?

Carp can be stopped surprisingly easily. A decade of peer-reviewed, published research has shown 4 techniques used in tandem would reliably and affordably stop up to 99% of all carp* from moving upstream in MN and WI, leaving so few adults that data shows it is highly unlikely they would reproduce.

  • Just as important as the techniques is the location. Barr Engineering Company (2022a) has shown that Pool 5 south of Lake Pepin near Winona, MN is ideal and also protects most of the river. Studies show Lock & Dam 5 below Pool 5 already stops about 80% of all upstream-moving fish, with Lock & Dam 4 stopping even more fish. Stopping carp at Lock & Dam 5/Pool 5 requires only small improvements. No other location will work nearly as well. (Lock and dam locations shown on map.)
  • The 4 techniques that published research has proven to stop carp, especially when used in tandem, are:
    1.  Installing a carp sound deterrent in the lock at Lock & Dam 5 (although a significant cost,** this might not be needed if the techniques above work, but new studies show this is up to 95% effective).
    2.  Removing adult invasive carp from Pool 5 (little additional cost as current removal efforts only need to be repeated at another site).
    3. Managing Pool 5 for existing predatory fish, such as largemouth bass, that would consume carp and their young (instituting catch and release).
    4. Adjusting spillway gates at Lock & Dam 5 and Lock & Dam 4 to further reduce carp passage (no cost to implement).
  • Simulations show these options–or parts of them–can be combined in many ways at this location, depending on the resources available.
  • If carp pass Pool 5, become established and breed, this promising scenario disappears. The next reasonable place to stop carp would be Lock & Dam 2 upstream of the St. Croix River, leaving the St. Croix unprotected.
  • No other scientifically proven solution has yet been identified.

*See Zielinski & Sorensen 2021 in References & resources.

**See Barr Engineering Co. 2022b in References & resources.

References & resources
The threat to our waters
Our team