DNR: Help Stop The Spread Of Starry Stonewort

DNR: Help Stop The Spread Of Starry Stonewort Click to Enlarge Photo: Minnesota DNR

(KNSI) - The Minnesota Department of Natural Resources is asking boaters to take precautions and help stop the spread of an invasive weed first found in a Stearns County lake.

As the 2019 fishing and boating season gets underway, the DNR's fight against the spread of starry stonewort, first found in Lake Kronis near Paynesville in 2015, continues.

Starry stonewort is an alga that looks similar to other native plants and can form dense mats, which can interfere with use of a lake and compete with native plants.

It is most likely spread when fragments of the weed havn't been properly cleaned from trailered boats, personal watercraft, docks, boat lifts, anchors or other water-related equipment.

Starry stonewort may double or triple in size within two to three years in a lake, once it becomes well established.

Since it was first discovered, starry stonewort has spread to at least 11 other lakes including Rice Lake near Paynesville and Grand Lake near Rockville.

Earlier this month, the DNR said they've been able to contain the infestation on Grand Lake.

The DNR formed a starry stonewort guidance group in 2017 to review, permit and evaluate control projects.

The agency is issuing permits for pilot projects, working with local governments, lake associations and partnering with researchers to limit starry stonewort's spread.

Their efforts include control of starry stonewort using hand removal, equipment, and copper herbicide treatments; evaluating the relative effectiveness of these methods; learning more about the biology of starry stonewort; working with lake associations and volunteer groups for early detection and monitoring; and educating boaters and anglers about how to prevent spreading starry stonewort and other invasive species.

Hand removal by divers in small, localized areas appears to be effective, if done carefully. Repeated hand-pulling efforts or follow-up copper treatments may be necessary. Similar to other invasive plants in Minnesota, starry stonewort requires management on an annual basis.

The DNR reminds boaters and anglers to follow Minnesota laws to prevent the spread of aquatic invasive species:

Clean aquatic plants and animals from watercraft.

Drain all water by removing drain plugs and keep drain plugs out while transporting watercraft.

Dispose of unwanted bait in the trash.

Some invasive species are small and difficult to see at the access. To remove or kill them, take one or more of the following precautions before moving to another body of water, especially after leaving infested waters:

Spray with high-pressure water.

Rinse with very hot water (120 degrees for at least two minutes or 140 degrees for at least 10 seconds).

Dry for at least five days.

For more on aquatic invasive species, click here.

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