DETROIT LAKES, Minn. – Move over flowering rush, a new invasive species is now threatening Minnesota lakes – and Big Detroit may be especially vulnerable.

Starry stonewort may sound like something that pixies sprinkle from their magic bags to make you go to sleep at night, but it is actually grass-like algae, which produce dense mats that interfere with recreational use, choke out native plants, and have other impacts that alter lake habitat.

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That's according to the DNR, which is taking further steps to reduce the risk of starry stonewort spreading to new lakes, in response to the discovery of starry stonewort in Lake Koronis in Stearns County.

The DNR will treat the invasive algae in front of the main public access at Lake Koronis, as part of an expanded effort to reduce the risk that it will spread to other bodies of water.

The treatment will be monitored for its effectiveness in reducing the existing mats of starry stonewort, making it less likely the algae will be picked up by boats as they exit the access.

Lake Koronis and Mud Lake, connected to Koronis, are the only Minnesota water bodies with confirmed infestations of starry stonewort.

But Big Detroit Lake could be a target for starry stonewort, since a similar native plant does very well there, said Steve McComas, owner of Blue Water Science in St. Paul. He is a scientist sometimes dubbed "the lake detective" for his work in invasive species and lake ecology.

"We don't know much about this plant," he said of starry stonewort. "It's not as well-studied as other plants. We don't know what the main (growth) drivers are - where does it do best? Where are there limitations? There are always barriers out there for plants, we don't know what they are for starry stonewort."

He said Big Detroit Lake is fertile ground for chara, which is often called muskgrass or skunkweed because of its foul, musty almost garlic-like odor.

"It (chara) is certainly a noticeable player in Big Detroit Lake," McComas said. "There are times it rolls in almost like tumbleweed ... Chara can grow pretty thick in big beds," he added. "When the wind comes in shallow water it rolls up to shore, it can impact navigation."

Chara is a gray-green branched multicellular alga that is often confused with submerged flowering plants.

"Starry stonewort is in the same family as chara," McComas said. "So it has the potential to grow like that ... It's a macro algae; it's an interesting plant, that's for sure, so is chara. We've been looking at what makes chara so successful in some lakes."

He says that starry stonewort "will be a player to be reckoned with" among invasive species, but "probably won't cause the problems produced by the Big Four-Curly-leaf pondweed, Eurasian watermilfoil, zebra mussels and invasive carp."

The bottom line on starry stonewort? "We want to act, but not over-react," he said.

As with all invasives, the key is to find the drivers behind "super-growth," he said. Not all invasives flourish in all lakes.

He recently participated in an extensive survey of zebra mussels in Big Cormorant Lake, for example.

The DNR and McComas spent over 80 hours diving in Big Cormorant - they inspected over 20,000 items and only three were found to be zebra mussels.

It may just be that the lake is early in the infestation phase, but it could also mean Big Cormorant is not conducive to super-growth of zebra mussels, he said, perhaps because the low algae count there doesn't give zebra mussels much to eat.

Either way, nature has a way of balancing things out over time, he said.

"A lot of these new species go wild for a few years, but Mother Nature catches up in a hurry," he said. "There are checks and balances out there-it's hard to dominate forever."