Northern Wisconsin's identity is deeply tied to its abundant and beautiful lakes and rivers – essential resources for ecological health, recreation, and local economies. These waters, however, face a persistent threat: aquatic invasive species (AIS). Among these, the spiny waterflea, an NR40 prohibited invasive species, making it illegal to possess, transport, transfer or introduce. 

Spiny waterfleas are a type of invasive zooplankton, tiny animals that drift in the water. While visible to the naked eye, they are translucent and easy to miss. They are also predators, consuming native Wisconsin zooplankton. This predation reduces the biomass of native zooplankton, altering the food web and potentially leading to reduced water clarity and negative impacts on fish species like walleye, which can become smaller and less abundant in infested lakes. 

This tiny invader is already present in Lake Superior, the St. Louis River Estuary, and the Gile Flowage in Iron County. However, a recent, proactive prevention campaign demonstrates how localized efforts, fueled by community engagement, can effectively push back against the spread of these harmful species.

The "Stop Spiny!" project for Northern Wisconsin, led by Zach Stewart of the Douglas County Surface Waters Program, was born from the recognition that while spiny waterfleas are present in a few regional water bodies, hundreds, even thousands, of others remain unaffected. “Douglas County has 427 water bodies, and preventing the spiny waterflea from entering even one is worthwhile,” said Stewart. His mission to protect these lakes and rivers motivated the campaign, recognizing an opportunity to act early.

Preventing the spread of spiny waterfleas presents challenges, especially as recreation brings people and their equipment to different lakes. Boats, kayaks, and fishing gear can inadvertently carry spiny waterfleas or their resting eggs, which settle in mud, moving from one water body to another on equipment. “The campaign's approach is to encourage people to visit and enjoy the waters,” explained Stewart, “and to ensure they understood the critical importance of cleaning, draining, and drying their equipment.”

The "Stop Spiny!" campaign adopted a multifaceted strategy, with a twofold key message: first, to educate people about spiny waterfleas, and second, to motivate them to protect against this threat by cleaning, draining, and drying equipment. 

Douglas County took their message directly to the public, presenting detailed talks to everyone from professionals to elementary school students to local lake associations. Rather than simply telling people what to do, these presentations dove deep into the spiny waterflea's story--where it came from, how it reproduces, what conditions it thrives in, and why it's such an effective predator. 

"If you spend time learning the fascinating science behind this animal and where it came from, I believe that it sticks in people's minds,” Stewart explained. “When they're fishing and exploring our lakes, they'll remember those interesting facts, maybe share it with others, and help build a social norm of AIS prevention hygiene.” 

The outreach campaign cast a wide net, posting on social media, distributing flyers, and working with local news outlets to get the word out. Radio announcements were strategically timed around Wisconsin's fishing opener, when thousands of anglers would be hitting the water.

But perhaps the most clever innovation was also the most practical: a specialized cleaning cloth. These cloths become absorbent and tacky when wet, making them perfect for cleaning fishing lines - which happen to be one of the main ways spiny waterfleas spread. The tiny invaders' spiny bodies easily snag onto fishing line, hitching rides from lake to lake. 

Distributed at boat launches and fishing events, Stewart explained the cloths served triple duty. “They actually worked to remove the waterfleas, they got people talking, and they’re a memory cue for the problem every time someone reaches for their tackle box.”

The campaign also recognized that some of the most important conversations happen one-on-one at the water's edge. Clean Boats Clean Waters (CBCW) workers–the staff and volunteers who inspect boats at public launches–meet hundreds of people each summer. They were provided with specialized training, turning these frontline workers into "mini experts" who could share detailed information about spiny waterfleas with every boater and angler they encountered.

Stewart notes that none of this would have been possible without an extensive network of partners. While housed and led by Douglas County, the campaign received significant funding from the Wisconsin DNR's Surface Waters Grants Program and the Wisconsin Natural Resources Foundation. The Minnesota Aquatic Invasive Species Research Center also provided crucial support and donated digital materials. Critically, the four Lake Superior counties–Iron, Ashland, Bayfield, and Douglas–were major partners, alongside many local lake associations and conservation groups. It was truly a community effort, without which the work wouldn't be possible. “The community members and people who recreate on our waters are the most valuable asset and your biggest teammates,” Stewart emphasized.

The campaign has reached nearly 22,000 people–impressive numbers that reflect something deeper about northern Wisconsin. "People are passionate about our lakes and rivers," Stewart explains. "This personal interest means that information about protecting these cherished waters is valuable to Wisconsinites."

That connection explains the campaign's most important result: there has been no widespread expansion of spiny waterfleas in the project area. Stewart believes the combination of engaging science communication, community partnerships, and practical tools has empowered people to protect their waters–and the lack of spread suggests it's working.

The successful "Stop Spiny!" project offers a blueprint for other communities facing similar threats. By making science accessible, building local partnerships, and giving people practical tools, the campaign has shown that communities can take control of invasive species prevention. And while the focus was on one tiny predator, the habits it's helping to build–clean, drain, dry– protect against all aquatic invaders.