TOPEKA (KSNT) – A tiny species is making a big impact in Kansas’ creeks and lakes.

Many waterways in Kansas are infested with an invasive species that has proven to be nearly impossible to remove, despite the best efforts of biologists. This species costs the Sunflower State millions of dollars every year, according to information from the Kansas Department of Wildlife and Parks (KDWP), and is showing no signs of going anywhere anytime soon.

KSNT 27 News spoke with wildlife experts about the impact of the notorious and widespread zebra mussel infestation and what’s being done to stop their growth.

What are zebra mussels?

According to the KDWP’s website, zebra mussels have the appearance of small clams that are around an inch or less in length with a D-shaped shell. These mussels are usually yellow-brown in coloration with alternating dark and light stripes. Once zebra mussel larvae reach adulthood, they latch onto hard, nonmoving objects and start to filter feed.

A zebra mussel being measured. (Photo Courtesy/USFWS)

Zebra mussels like to live on solid structures and eat plankton in the water, taking away valuable resources for natural Kansas aquatic species, like some invasive species of carp also inhabiting waterbodies in the state. According to the KDWP’s website, this filtering action by the mussels does not necessarily result in clean water, even though it may appear clear.

Vanessa Salazar, Aquatic Invasive Species Biologist with the KDWP, said this strain of mussels comes from the Black and Caspian sea in Europe. They were first introduced to American waters in 1988 by ships on the Great Lakes.

“They’ve only been here 20 years, that’s not a very long time,” Salazar said. “In the Great Lakes, they’ve been there over 40 years. Once you have one invader, it opens the door to other invaders.”

Salazar said the mussels were first spotted in Kansas in 2003 at the El Dorado reservoir. From there, they have successfully spread to 35 other waterbodies in Kansas, likely from boaters traveling between waterbodies. A report from the Associated Press (AP) on the detection of the mussels in a popular Nebraska lake linked their arrival to boaters giving the invasive species the opportunity to “hitchhike” across the country.

Map dated May, 2022. (Photo Courtesy/KDWP)

According to a report from the U.S. Geological Survey (USGS), once zebra mussels are established in one area, the likelihood of them spreading to nearby waterbodies increases. This poses great risks to local animal life and can lead to health hazards for humans.

Why are they a problem?

Zebra mussels pose many problems not just to the wildlife of Kansas, but also to many residents. The U.S. Fish and Wildlife Service (USFWS) considers them to be one of the most destructive invasive species in North America, and not without good reason.

“I would definitley say zebra mussels are the biggest threat,” Salazar said. “They are the most costly… they cost Kansas about $8 million or more in costs each year.”

Salazar said water treatment plants and power plants are hit hard by the mussels because they tend to gather in pipes beneath the facilities, clogging them up. Workers then need to remove the mussels while the plants are forced to adapt their maintenance strategies in response to the infestation.

A boat propeller covered in zebra mussels. (Photo Courtesy/USFWS)

According to the KDWP’s website, zebra mussels cost power plants more than $145 million every year. Salazar said this results in a “trickle down” effect that lands additional costs on consumers.

“What a lot of people don’t realize, if a water system is impacted by zebra mussels… if they infest a waterbody that is a water source, it causes an increase in people’s water bills and that is something that is often overlooked,” Salazar said.

Once the mussels have infested a waterbody, they are nearly impossible to remove. According to the KDWP’s website, chemicals can be used to kill off the invasive mussels, but this can pose risks to native aquatic species as well.

“There has been some research done recently,” Salazar said. “If you want to exterminate zebra mussels, it requires the death of all other mussel species in the water.”

According to the KDWP’s website, the mussels filter feed while in the water, sucking up nutrients like plankton that native species rely on for sources of food. This filtering effect leaves the water clearer than it was before, which can lead to the destruction of fish eggs due to more prevalent UV rays from the sun. The mussels can also lead to more harmful algal blooms which bring higher levels of toxicity to Kansas waterbodies.

“They’re very successful invaders because they thrive in many different environments and breed quite prolifically,” Salazar said. “A single female can create more than a million eggs per year. The larvae is microscopic and they have no natural predators.”

What can be done to stop their spread?

While there aren’t many options to remove zebra mussels once they infest a waterbody, there are measures that Kansans can take to ensure their spread is slowed. Salazar encourages people to use best practices when dealing with zebra mussels. This includes draining all water from boats, live wells and bait wells. Boaters should also thoroughly inspect their hulls and trailers for any zebra mussels and remove them.

“Cleaning and draining and drying is the best thing that will reduce the spread of any aquatic invasive species,” Salazar said. “Don’t transport water. It’s best to assume the water is infested.”

According to the KDWP’s website, equipment should be washed with 140-degree water and/or be allowed to sit for five days. Fish and plants should never be transported from one waterbody to another. Also, never dip bait buckets into a lake or river if it has water in it from another waterbody, especially one that is infested with zebra mussels.

Salazar said barriers like dams can stop the mussels from moving to other waterbodies but a flood could provide them with the ability to move to new territory. For now, KDWP biologists continue to monitor Kansas waterbodies for any signs that the mussels are expanding and warn people about the hazards associated with them.

If you find zebra mussels in a Kansas waterbody, you are encouraged to not release them back into the water. According to the KDWP’s website, you should write down the date and location before calling the Emporia Research Office at 620-342-0658 or by going online to report an aquatic nuisance species.