Slowing the spread of zebra mussels in South Dakota

Shane Pedersen
South Dakota Game, Fish and Parks Conservation Officer

With the recent discovery of zebra mussels in Lake Sharpe people are wondering how we can prevent the spread of this invasive species. Historically, zebra mussels made their way into the great lakes around the 1980’s in ballast tanks of large ships from Europe. As the years went on the invasive species continue to expand out of the Great lakes into the large rivers of the eastern Mississippi drainage basin. Through this expansion zebra mussels have been creating havoc not only on the water ecosystem, but also restricting water movement on hydroelectricity intakes and intake structures for drinking and irrigation systems.

Some may wonder what the life cycle of the zebra mussel is. In one year an adult zebra mussel can produce up to one million eggs. The young zebra mussels also known as veligers, are smaller than the width of a human hair and nearly impossible to detect due to their size. A veliger can float on top of the water for up to a month; making it easy for zebra mussels to spread. With the veligers being small they can find their way into boat motors, live wells and any other items that are in contact with the contaminated water.

Zebra mussels are known filter feeders they primarily feed on plankton and other microorganisms in the water column. These are the same sources of nutrients that are required by juvenile fish. During the life cycle an adult zebra mussel can filter an estimated one liter of water per day.

So how do we slow the spread of Zebra mussels? To help slow the movement it is required for all boaters and anglers to drain all water by removing all drains, plugs, bailers, or valves that retain water before they leave the launch area. Make sure all watercrafts and trailers are free of any aquatic plants and mud. If recreating on contaminated water make sure the boat is completely dry for at least 5 days before launching in any other waters.

With a combined effort from all users of South Dakota waters we can help slow the spread of this invasive species.