Battling the Big Waves of Johnson Lake

by Riley Steinbrenner

Photo: Riley Steinbrenner

Just outside of Minocqua, Wisconsin, we drove up to the Johnson Lake boat launch and you could see them clear as day.

No, not the different species of macrophytes, or aquatic plants, we were after, but wind-driven white caps.

White caps may be a promising sign of catching some gnarly waves in the ocean, but for a scientist hoping to catch some gnarly macrophyte samples from a flat-bottomed boat in the middle of a lake, they pose more of a hassle than help.

On less windy days, the visibility below the water’s surface is pretty clear until about 15 feet, Susan said.

Today was not one of those days.

After settling the boat on the lake’s edge, we started paddling our rickety row boat against the whistling wind.

I was in charge of documenting our plant species while Susan hunted for samples. Photo: Adam Hinterthuer

It was my first day on the job as the summer science communication intern at the Center for Limnology’s Trout Lake Station. Susan Knight, the station’s interim director, needed to collect samples for an upcoming plant ID workshop. Adam Hinterthuer, the CFL’s outreach and communications specialist, thought it would be a good idea to tag along.

“This isn’t going to be ‘On Golden Pond,'” I thought.

Having taken a few jabs at the white caps, Adam anchored his oar into the soft sediment below and Susan went head first into her sampling—literally.

Donning a pair of goggles, Susan plunged her face into the water. Upon resurfacing, the look on her face and toss of the goggles back into the bucket said it all. With turbid waters churning the sediment below, the goggles would not be useful this go-around.

Instead, using a mini, red rake reminiscent of the one kids use to help their parents do some backyard “fall cleaning”, Susan blindly swept the waters for plants from the bow of the boat.

Susan Knight rakes out and inspects a plant sample for identifiable characteristics. Photo: Riley Steinbrenner

All of a sudden, I turned around to see a dark, green, soppy mess held at eye-level in Susan’s hand.

“What does this smell like?” she asked. Not a question one would expect on a plant hunt.

Breaking the most basic rule of Chemistry 101, I took a big whiff of the mucky stuff dripping with a dressing of stark black sediment that streamed down my forearm and handed it over to Adam in distaste.

With a wrinkle of our noses, we let out a weak reply to the cringe-inducing odor.

“…Skuuuunk.”

This foul-smelling algae is not something you would want to find floating around your lake, Susan said. It is, however, one she wanted to find on her Latin laundry-list of macrophytes.

“Kahra!” was all we could make out as the Latin name of this algae as western winds winnowed Susan’s words into a nearly inaudible string of inflections by the time they reached the boat’s stern.

Adam’s eye bounced up and down the water-speckled checklist until they locked in on the top half.

Chara.

A sample of mostly Chara. Photo: Riley Steinbrenner

With a smooth glide and check from a wooden pencil tethered to the clipboard, we were making progress—even though our position from where we docked probably wouldn’t give that impression!

Despite getting shoved to shore by the fetch, or wavy part of the lake, it actually worked in our favor by navigating us right into the littoral zone.

The littoral zone, literally means “near shore” but, to Susan, it means “where the plants grow.” And the first 15 feet out from shore, particularly on Johnson Lake, is a macrophyte goldmine.

As we tossed and bobbed in the waves, Susan collected species such as Potamogeton richardsonii, a type of pondweed, and Myriophyllum alterniflorum, a non-invasive type of watermilfoil.

A banded mystery snail. Photo: Riley Steinbrenner

For fun, Susan found Sagittaria latifolia, a plant commonly known as duck-potato with bare, edible bulbs that were often consumed by Native Americans and, yes, also ducks.

At one point, an invasive type of snail called a banded mystery snail even hitched a ride!

The only mysterious part about these guys seems to be how to get rid of them—they are invasive, meaning not native to the area. And, while they haven’t exhibited the same negative impacts of more infamous invasives, like zebra mussels, it’s still best not to throw them back into the water.

Johnson Lake is one of Susan’s favorite places to collect plant samples because there are so many species living in such close proximity. In an area no larger than a basketball court, we ended up collecting around 15 different macrophyte species for her identification workshop. It was enough for one windy day. She’ll head to a different lake in calmer weather.

Potamogeton richardsonii, a type of pondweed. Photo: Riley Steinbrenner

Now that the hard part was over, the easy part was getting back to shore. Thanks to the western winds, we only had to use our oars to turn around, and we were pushed back to the sandy shore of Johnson Lake in no time.

Like all responsible boaters do, Susan rinsed the bottom of the boat with a solution of water and bleach, which the Wisconsin DNR has found to be the most effective solution in preventing cross-contamination of diseases between lakes, she said.

After a thorough clean, it was back to Trout Lake Station where Susan will start sifting and organizing the plant samples and I could take stock of everything I’d seen in just my first morning on the job.

Although it was not your typical tranquil day on the lake, it was a fun adventure to get a glimpse of the diversity in plant species that Johnson Lake has to offer!

Adam Hinterthuer helps Susan Knight give the boat a thorough cleaning of bleach before towing it back to Trout Lake Station. Photo: Riley Steinbrenner

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