Zebra mussels are not large, but the damage they do to a body of water is huge, causing tremendous environmental problems as they expand their way throughout the upper Midwest.
(Photo courtesy of the South Dakota Game, Fish and Parks)
It’s spring where spending time on the water is very inviting, it’s also a time of year where the threat of spreading zebra mussels is high.
Zebra mussels derive their name from the dark, zig-zagged stripes on their shells, which resemble the stripes on a zebra.
The invasive species, the Zebra Mussels, are a fingernail-sized mollusk, a small clam, ranging from one eighth to two inches in length, causing tremendous environmental problems and are expanding throughout the upper Midwest.
It’s believed that they came into the United States via the Great Lakes in 1988 and were released when ballast water was discharged by large ships coming in from Europe.
Zebra mussel have hitchhiked their way, mostly on boats, throughout the Mississippi and Missouri River watersheds, with populations now known to exist in at least 23 states, primarily within the Great Lakes and Mississippi River watersheds.
Zebra mussels are very prolific, as females can produce up to one million eggs per summer, with their fertilized eggs develop into free-swimming larvae called veligers. These veligers are not visible to the naked eye and are only about the width of a human hair.
Before they develop, the Juvenile zebra mussels, called veligers, that can be spread unknowingly through water released from your live well or from water discharge through the bilge pump.
In just two to three weeks, the veligers begin to ‘settle-out’ in the water under the weight of their shells and attach to firm, underwater surfaces.
Once attached it takes approximately one year for the mussel to grow an inch and become sexually mature.
They grow in clusters and can reach over 100,000 individuals per square meter, generally found in the shallow, six to thirty foot in algae-rich water.
They attach to hard surfaces because of the tuft of fibers located at the hinge of their shell called byssal threads.
These threads produce powerful glue that anchors the mussel in place, with any hard surface working for a mussel to live on, including rock, metal, wood, vinyl, glass, rubber, fiberglass, or paper.
Zebra mussels may even colonize living organisms such as plants, other mussels, and the bodies of slow-moving animals like turtles with the zebra mussels having the ability to live from two to five years.
These invasive mussels negatively impact our ecosystems in numerous ways as they disrupt the food chain, leading to a drop in population of key fish species, creating dense colonies on surfaces.
These clog intake valves including water intakes used by Rural Water systems and Power Plants who have to spend millions of dollars removing these mussels from clogged water intakes.
and leaving razorlike edges on piers and shorelines.
With their population explosion, they fundamentally alter a lake, making the water clearer, changing the type of vegetation and other aquatic life that can survive.
The Missouri River and its s as well as others have been infested with zebra mussels since 2015, with both the Nebraska Game & Fish and the South Dakota Game Fish & Parks developing programs which they ‘d hoped would prevent the mussels from expanding their territory and spreading into Lewis & Clark Lake.
Now, the Game, Fish and Parks indicate that a 5-gallon pail of water taken from Lewis and Clark Reservoir carried an average of 900 veligers.
Lewis & Clark Lake is not the only Missouri River reservoir to be invaded by the zebra mussel as the South Dakota Department of Game, Fish & Parks has also confirmed the presence of zebra mussels in Lake Sharpe, a reservoir in central South Dakota.
It seems as if these mussels, piggy-back onto boats coming out of infested waters, in the live wells and bilge water left in the boat.
Zebra Mussels have not just infested the Missouri River and its tributaries as in Nebraska they have been found their way into the Omaha area in Zorinsky Lake, Carter Lake, the lake at Offutt Air Force Base and will more than likely be found in other bodies of water.
Recently in northeastern part of South Dakota, in Duel County near Gary, South Dakota, zebra mussels were found in Lake Cochrane as well as in in Codington county Lake Kampeska near my hometown of Watertown and will undoubtably be found in other lakes in the state.
These newly discovered zebra mussels in South Dakota and Nebraska increase the need for formal boat inspection programs in both states to reduce the risk of the spread of these mussels to other water bodies.
The best way to prevent zebra mussels from spreading is to employ the “Clean, Drain and Dry” protocol for all boats, trailers and equipment between uses by following these steps:
· Inspect the boat, trailer and all equipment and Clean watercraft and trailers of all aquatic plants and mud.
Drain all water by removing all drains, plugs, bailers, or valves that retain water. Be sure to completely drain your lower unit of any water by lowering it completely.
Discard unwanted bait in trash or fish cleaning stations when leaving the water
Dry your boat and equipment for 5 days before launching into another water body, with
specific decontamination requirements for boats kept in the waters continuously for three or more days, or that cannot have all water drained from them.
These are not just suggested rules, they’re the law, so you are not only helping save our resource, you are potentially saving yourself some money, as boats found to be transporting zebra mussels can be impounded and the owners fined up to five hundred dollars.
Completely draining a boat is the first step in making sure invasive species are not transferred to other waters.
For more information on zebra mussels, other aquatic invasive species, and how to properly decontaminate your watercraft, visit sdleastwanted.com.
Gary Howey is an award-winning writer, producer, and broadcaster and inducted into the “National Freshwater Fishing Hall of Fame” in 2017. He developed and was the Producer- Host of the Outdoorsmen Adventures television series for 23 years and is the Co-Host of the award-winning Outdoor Adventures radio show. If you’re looking for more outdoor information, check out garyhoweysoutdoors.com, and outdoorsmenadventures.com, with more information on these pages, Gary Howey’s Facebook page, Outdoor Adventure radio and Team Outdoorsmen Productions Facebook page. The Outdoor Adventures television show is available on the MIDCO Sports Network, and News Channel Nebraska.