An invasive aquatic species has hitched its way to Naperville.
For many months, during Riverwalk Commission meetings, Chuck Papanos, Operations Manager for the Riverwalk, has reported on findings of nonnative zebra mussels in the deep pond known as the “Paddleboat Quarry.”
In late May, PN observed a team under the leadership of Jessi DeMartini, Research Center Coordinator, fondly known as “Mother Earth,” as they visited the quarry, venturing out on a paddleboat to collect samples.
Simply put, a mussel, also known as a bivalve mollusk, is a water animal with a soft body inside a hard, protective shell. Ranging in a variety of sizes, mussels live in oceans, estuaries and brackish to fresh water. Their two-piece shell is joined by a hinge so it can open and close.
How they hitched a ride
Indigenous to the Caspian and Black Seas in southern Russia, zebra mussels can breed relentlessly, producing nearly a million eggs in a single season.
Distinguished by its striped exterior shell, the zebra mussel (about the size of a fingernail) was first discovered last year in Naperville – by the thousands – on the bottom of the paddleboats when they were removed from the quarry after the summer season.
Those findings led to contacting the Forest Preserve District of DuPage County and a team confirmed the presence of a large mussel population, likely growing there for about four years which was determined by their size.
In 2009, The Forest Preserve District of DuPage County first confirmed the presence of zebra mussels in the region at Deep Quarry Lake and Bass Lake located within West Branch Forest Preserve in Bartlett. Currently the District staff and volunteers under the Protect Your Waters program monitor mussel populations throughout the county.
Papanos watched and listened as zebra mussels were harvested from the depths by DeMartini’s team from the Urban Stream Research Center, then delivered to shore where the invasive creatures were measured and studied near the entrance to the Paddleboat Quarry.
By contrast to the invasive zebra mussel, DeMartini explained that native freshwater mussels that survive in rivers and streams help keep the water clean and free of pollutants. There are nearly two dozen indigenous species that can be found in the Fox River Basin.
The aquatic invasive species monitoring and education program, including the District’s Protect Your Waters volunteer program, monitors waterways for zebra mussels and seeks to educate the local citizenry about preventing the spread of nonnative plants and animals.
Zebra mussels can lay over 30,000 eggs in a reproductive cycle, undergoing many cycles within a year. The microscopic larvae then gravitate and land upon hard services. They anchor themselves to hard surfaces via strong byssal threads. Incredibly resilient, they can live out of water up to a week.
According to DeMartini, wearing waders that she said would be rinsed thoroughly in salt water or vinegar before worn again, the zebra mussel has spread across the United States by attaching to watercraft and the inside of bait buckets.
First discovered in North America in the late 1980’s, the mussels have spread to over 20 states, concentrated around the Great Lakes and Mississippi River. The most likely hitched a ride in ballast water from ships originating in Russia.
Why we should care
Large populations of zebra mussels can filter all of the water in the quarry in one day, consuming plankton that native species and fish rely on for food. In other infested water systems, the water can become too clear for light-sensitive fish, causing them to move to deeper waters, including walleye.
The prolific nature of nonnative breeders harms native mussel populations by interfering with feeding, DeMartini noted.
Some native waterfowl and fish also feed on zebra mussels, but they don’t consume enough to control populations.
If the population spreads, the mussels can wreak economic havoc with waste water management, power and flood control facilities, not to mention reservoirs, with costs associated with removing the population.
Molluscicides and other treatment methods are estimated to cost the Great Lakes region about $100 to $400 million annually, according to the District’s website.
For more info, visit www.dupageforest.com.
Don’t feed the wildlife
The Naperville Riverwalk offers a natural treasure of experiences every day. No matter what the season, the winding brick path that follows the DuPage River, leading to deep quarries, also shows signs that the park is chock full of ducks, geese, waterfowl and wildlife.
The dirty droppings are one of the reasons the Riverwalk Commission, Riverwalk Foundation and Naperville Park District have been on a campaign to create awareness with a message “Don’t Feed Wildlife.” In addition to uncleanliness, feeding human snacks and bread crumbs to ducks and geese is deleterious to their health and interrupts the food chain.
