Invasive Carp and Lock Usage

Upper St. Anthony Falls Lock and Dam

If you are a boater and you must travel from one pool to another, consider trailering your watercraft around the lock instead of going through it.

The National Park Service is working to slow the advance of invasive carp into the Mississippi River watershed north of the Twin Cities. The Park Service believes that using the locks will allow passage of these fish to uninfested waters.

Upper St. Anthony Falls Lock and Dam and Lock and Dam No.1 are two of the highest dams on the upper Mississippi River, at 49 feet tall and 36 feet tall, respectively. The only way carp can pass them is to swim through the locks when they open to pass a boat. The distance between the water above and below the dam is far enough that a carp can't jump over the dam, even during floods. Therefore, minimizing lock use will limit invasive carp traveling farther north on the Mississippi.

Upper St. Anthony Falls Lock and Dam and Lock and Dam No. 1 are two of the northern-most dams capable of stopping carp movement - the last strong defenses against these northward moving fish. If invasive carp are allowed north of the Upper St. Anthony Falls Lock and Dam and Lock and Dam No. 1, these fish will not have much difficulty moving the rest of the way up the Mississippi River. If left unchecked, invasive carp may find their way into lakes such as Itasca, Mille Lacs, Bemidji, and other Mississippi River tributaries.

Invasive carp are known to out-compete native fish for food and habitat, which can drastically lower the native species' numbers and health. This includes native game fish, such as bass, walleye, and northern pike. To add to the problem, silver carp (one of the four invasive carp species) are known to jump up to 10 feet out of the water when startled. At 40 pounds or more, they can seriously injure boaters and damage boats and equipment.

Invasive carp aren't the only problem. Other invasive species, like zebra mussels and Eurasian water milfoil, can hitch rides through locks as well.

We can all do our part to help prevent the spread of the invasive carp and other invasives!

Last updated: March 6, 2023

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