The South Dakota Game, Fish and Parks (GFP) Commission recently proposed new aquatic invasive species (AIS) rules and modifications to the existing ones in an effort to target the most likely ways these species are moved from lake to lake. Two current AIS rules have also been modified to ensure anglers and boaters have the opportunity to easily comply with the regulations.

“There are currently only three waters in the state where zebra mussels are present, therefore it is essential that efforts focus on containing the mussels at these waters and slowing their spread to additional water bodies,” stated Kelly Hepler, GFP department secretary. “The population of zebra mussels has rapidly expanded in Lewis and Clark Lake. Surveys have shown that from 2015 to 2016 significantly more boats that are stored in the lake are heavily infested. The number, size and attachment location of the mussels and their larvae make decontamination efforts extremely difficult.”

New rules
Containment waters: The Commission proposed classifying selected water bodies with AIS as “Containment Waters.” This designation will allow for subsequent regulations to refer specifically to these waters.

Local boat registries: The Commission proposed authorizing the department to create “Local Boat Registries” at containment waters. Initial plans for Local Boat Registries include a “free-transportation zone” where boats may be transported without being decontaminated as well as provisions in place for allowing over-winter boat storage with AIS attached to the vessel. Boats included in the registry may not launch into any other water body or be transported outside the transportation zone without being decontaminated.

Residual water decontamination: One of the top ways zebra mussels spread is through the transport of water infested with zebra mussel larvae (veligers). Many types of recreational boats, such as wakeboard boats, are equipped with one or more ballast tanks that hold water to create a larger wake for stunts and tricks. Due to their design, most of these tanks cannot be fully drained of water. If a wakeboard boat is used on infested waters, the ballast tanks can hold veligers that could then make their way into the next body of water visited. In an effort to limit the movement of water, the Commission proposed a new rule that requires boat owners whose boats have been removed from containment water, and are holding 1or more gallons of water, to decontaminate those boats before they can be launched again.

Moored boats: Boats that are moored or stored in a containment water area have a higher likelihood of becoming infested with zebra mussels. Zebra mussels can reproduce from May through mid-November in South Dakota. This time period encompasses nearly the entire boating season, so anytime that a boat sits in infested waters for more than a few days it is possible that mussels will attach to it. The Commission proposed a new rule that would require decontamination of boats stored in a containment water for three or more days. This decontamination must be completed before the boat is launched on the next trip.

Modifications to current rules

AIS restrictions: The Commission proposed including two additional exceptions to the AIS possession and transportation restrictions. Participants in a local boat registry and department-approved businesses would be permitted to possess and transport boats with AIS attached or on board.

Watercraft restrictions: The Commission proposed additional language to this rule that would allow participants in a local boat registry to launch their boats into the water listed in the registry with AIS attached. This means that a boater registered in the Lewis and Clark Lake Boat Registry could launch back into Lewis and Clark Lake without removing mussels that may be attached to the boat.