STILLWATER, Minn. (AP) — New restrictions on boating in the St. Croix River are the latest effort to prevent the spread of zebra mussels into the scenic waterway on the Minnesota-Wisconsin border.
Zebra mussels already infest the Mississippi River. They can kill native clams and compete with other aquatic life for food. They can travel by attaching themselves to boats and can foul beaches and water-intake pipes.
The National Park Service will staff a floating ranger station at the Arcola Sandbar on the St. Croix, which is between Stillwater and Marine on St. Croix and near the mouth of Wisconsin’s Apple River. Rangers will enforce restrictions that went into effect Sunday.
Boaters may travel upstream from the sandbar only if:
ù They have a Park Service permit, which is available to people who own land or live in the federally administered zone of the Lower St. Croix National Scenic Riverway.
ù They have a pass issued that day by an approved inspection point along the St. Croix.
Although the St. Croix is not infested with zebra mussels, they have been found on 51 boats moored on the river during the last two years. The Park Service said they became contaminated when they went on the Mississippi.
Signs will be posted at Prescott, Wis., where the St. Croix flows into the Mississippi, advising boaters of laws that prohibit transporting the mussels.
Boaters are being encouraged to avoid travel between the two rivers unless they make sure their vessels are zebra mussel-free. This can require high-pressure spraying with extremely hot water or keeping the boat out of water for seven warm and dry days.