Weed Wars: Inside Milfoil Battles On Glen Lake And Lake Leelanau (And A Koi Update)

The way Rob Karner sees it, things could be worse. Much worse.

The bad news is that the Glen Lake Association did in fact find the problematic invasive species Eurasian watermilfoil (EWM) in Little Glen Lake. The discovery came only about a month after the association gave a tentative all-clear following an extensive, multi-pronged search over many months.

But the great news is that crews found only four very small colonies, so the association can take action now to stave off a much larger infestation.

“There are regional lakes that have acres of this stuff, and the total square footage of all four colonies (in Little Glen) is 570 square feet,” Karner, biologist for the GLA, tells The Ticker. “The total bottomland of Little Glen is 62 million square feet.”

Karner says an earlier post made by the GLA that described a single infestation of 1,200 square feet was a rough estimate that has since been refined to a smaller number.

Now, the GLA is putting a plan into place to attack and eradicate the weed, Karner says, though they aren’t yet sure which of several methods (smothering with burlap, hand pulling, mechanically sucking, chemical treatments, etc.) they will use.

“We want to do what’s best, and we have some options,” Karner says. “At this point in time we have not completely landed on what we’re going to do.”

Association President Stan Kryder says GLA is in contact with other organizations in the area who have dealt with this problem in the past or are dealing with it now.

“We’ve reached out to different lake associations, and they’ve been open books with us in terms of sharing different techniques and practices,” he tells The Ticker. “We’re in the process of continuing our research to decide what’s appropriate.”

Among other positives are the ancillary benefits that came out of extensive surveying last year, Karner says. They now know where EWM is most likely to grow based on depth, proximity to native species and other factors, which will eliminate large swaths of the lake in future searches. They also now have detailed information about the location and quantity of many other species that inhabit the lake.

“We now have a much clearer picture of what’s going on down there,” Karner says.

In addition to eradicating the Little Glen colonies, Kryder said the association plans to put underwater drones in Fisher Lake (an offshoot of Big Glen Lake that is the source of the Crystal River) to check for EWM there after aerial drone surveying last fall. They’ll also conduct searches in Big Glen.

Karner and Kryder said the GLA will continue to lean heavily into its boat wash program, which aims to remove invasive species from boats before they enter the lake. This will continue to be important into the future, they say.

“A lot of lakes are spending a lot of money to get rid of it, but we’re spending a lot of money trying to make sure it doesn’t get into the lake in the first place,” Karner says. “We knew that some day that we would probably get EWM, just based on pure statistics and probability, but the boat wash (is the first line of defense).”

Meanwhile, the association will remain vigilant for invasive koi, the presence of which went viral last year in part due to pictures of the brilliantly orange fish making rounds on social media after being slain by bowhunters.

“There’s two key places in Little Glen that warm up first, so we’ll have our eyes and ears and drones out there looking in May for any remaining koi,” Kryder said. “We were successful last year in getting four, and we know we have to go out there again this year and double check.”

Karner says this year's hunt will be critical to determine if last year's fish were isolated or part of a larger population.

"If we work hard to try to get more and we don't get more, that's a good sign," he says. 

The neighboring Lake Leelanau Lake Association has been battling extensive infestations of EWM for several years. They’ve found success smothering it with burlap and have turned the tide in the war on this plant, though they remain on high alert.

“We basically classify our status right now as being in maintenance mode,” Annalise Povolo, LLLA’s director of administration and programs, tells The Ticker. “We’ve controlled all of the major infestations that we’ve identified… and at the end of last summer, we struggled to find any EWM growing in Lake Leelanau.”

Povolo said her team is standing by to help Glen Lake. Ultimately, she says, both lakes are in this fight together.

“We are very committed to assisting Glen Lake and sharing our knowledge with them. Threats that face our lakes in Leelanau County are shared threats because we have people going with their boats from lake to lake. And so any problems we have are potential problems for other lakes.”