Podcast shares the unexpected lessons of starry stonewort

Starry stonewort growing underwater.

Starry stonewort, and invasive aquatic algae, was first found in Wisconsin in 2014.

In 2014, Tom Reck was chairman of the Little Muskego Lake District when an invasive species made an unexpected appearance. It was the first time starry stonewort, an invasive macroalgae, had been found in Wisconsin.

“The problem was, we didn’t really know what was going to happen,” Reck recalled. At the time, little was known about how starry stonewort would behave — or how to control it. Media reports painted a dire picture, with one calling it the “start of the death of a lake.” 

Ten years later, starry stonewort’s status in Little Muskego hasn’t changed: it remains at the bottom of the lake despite robust efforts to remove it. But what experts know about managing invasive species has changed. 

In the newest season of “Introduced,” Wisconsin Sea Grant’s aquatic invasive species podcast, we not only learn how those experts are tackling the stonewort problem but how language, fear and human responses play a role in managing aquatic invasives.  

 

The power — and peril — of fear

Bret Shaw interviews for the Introduced podcast.

Bret Shaw discusses the risks of fear-based AIS messaging with Introduced. Photo: Wisconsin Sea Grant

Fear plays a major role in how people react to aquatic invasive species (AIS). Paul Skawinski, who was involved in the initial response to starry stonewort through his role at Extension Lakes, has since reflected on how AIS messaging has evolved.

“When I started working with AIS 20 years ago in 2004, people didn’t even know what an invasive species was,” said Skawinski. “[Natural resources professionals] really stressed how scary and damaging these species were.”

Fear-based AIS messaging is often based on an assumption that invasive species have devastating consequences in every lake, and aggressive action is necessary to eradicate or contain them. But research has proven that this isn’t always the case. Aquatic invasive species behave differently in different environments. 

“Sometimes they’re very aggressive, but sometimes they’re just integrated into the community and they don’t cause any real big issues,” said Skawinski.

Bret Shaw, a researcher at the University of Wisconsin–Madison, studies how communication influences environmental behavior. He recently collaborated with Wisconsin Sea Grant’s Tim Campbell to evaluate the effectiveness of fear-based AIS messaging, which often pushes lake management groups to consider aggressive herbicide use on their lake. Chemical treatment, however, carries its own risks and may harm native plants, disrupt ecosystems or possibly create better conditions for invasives.

“We want to avoid people creating ecological damage out of fear that’s not proportionate to the risk,” Shaw said.  

The importance of waiting and watching

How should one respond when a new invasive species is found in their lake or river? Paul Skawinski now recommends the “wait and see” approach. 

“Healthy, balanced lakes with a lot of healthy aquatic plants and healthy shorelines can often defend themselves pretty well against the invasion of a new species,” said Skawinski. “So waiting and watching is an important technique to try and has been pretty successful in Wisconsin.”

Tom Reck’s perspective has also shifted in the last 10 years. “Starry stonewort is a carpet on the bottom [of the lake], which is kind of nice when you’re boating or swimming instead of standing in muck,” said Reck. And although the future remains uncertain, he’s noticed that people around the lake have learned to live with it. 

“I’m not sure if it’s as bad as we thought,” said Reck.

To learn more about the story of starry stonewort, the science behind how humans react to new invaders, the consequences of fear-based messaging and the power of waiting and watching, listen to Introduced  available here or on your favorite podcast app.

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