They may not look like traditional detectives, but a new group of trained volunteers is ready to hit the lakes on the lookout for aquatic invaders.
More than a dozen volunteers spent a sunny summer day last week in a windowless basement in Brainerd learning how to identify invasive species and avoid being fooled by look-alikes.
They are the latest graduates from the AIS Detectors program, a joint project between the University of Minnesota Extension Service and the U's Aquatic Invasive Species Research Center.
The program has trained 125 detectors so far. The U hopes to certify another 100 in six more workshops next year.
About 5 percent of the state's lakes are listed as infested with aquatic invasive species, from zebra mussels to spiny waterflea. There's growing concern about new invaders like starry stonewort that are showing up in Minnesota lakes.
Megan Weber, a U extension educator, said the workshops have drawn a range of people from lakeshore owners to students to AIS professionals.
"It's really a nice mix of people who are interested in improving the world as it relates to aquatic invasive species," she said.
Once they're certified, the detectors will respond to new reports of invasive species. They'll take photos, collect samples and report back to the Department of Natural Resources.
The volunteer detectors learned to identify several different invaders, including plants, fish and invertebrates. They all have native look-alikes that can make it challenging to make a positive identification.
"It takes a little bit for them for us to be able to teach how to see those minute differences," Weber said. "What it comes down to often times is counting these tiny leaflets that come off of each leaf of the plant."
Like crime scene investigators, the volunteers use a tiny magnifying lens to get a closer look and compare the samples to photos in a waterproof handbook.
Some of the volunteers are lakeshore owners who signed up for the training because they're worried about their lake's future. Julie Hepburn has been coming to Lake Margaret near Brainerd her whole life.
"I'm concerned about the welfare of the lake and the future of Lake Margaret and the (Gull) chain," Hepburn said. "It's just really sad to see what's happening right now. That's why it's so great to see all these people here."
Kit Ferber lives on Big Fish Lake near Cold Spring, a clean lake without invasive species. Ferber said she wants it to stay that way.
"I've just heard a lot of stories about AIS, and I want to be able to identify it when I hear that there may or may not be something on the lake," Ferber said. "I didn't want to depend on the DNR if they can't make it out. I wanted to be able to be the first one that they can call."
The DNR has just 10 invasive species specialists to cover all the state's 13 million surface acres of water.
Stearns County invasive species coordinator Sue McGuire said there are more than 200 lakes in her county, and one DNR specialist who oversees three counties.
"There just aren't enough people whose job it is to be out there looking," McGuire said. "So the local residents, it's really important for them to be able to identify too and be aware of the issues."
Weber said having more detectors will mean being able to respond more quickly to new reports of invasive species. The volunteers can use a smartphone app to report the information.
"The sooner than you can find a new aquatic invasive species in a lake, the better your chances are for being able to respond to it," Weber said. "If there's a potential for eradication, that's when you have it is when it's a new invader and it has not spread throughout the lake. So having more eyes out there to find these things is really important."