Blog Redux: Fish Ears, “Tree” Rings and a Sectioning Saw

We thought we’d dig through the archives to see what we were up to in previous Novembers. Enjoy this look at “Limno in the Lab” from four years ago!

Aaron Koning uses a sectioning saw to cut a slice of otolith that will be mounted on a slide and polished, enabling him to see it clearly under a microscope.

Originally posted 11/13/12 – After the spring and summer field seasons, it’s time to return to the lab to work up all the specimens collected in the field. For many grad students at the Center for Limnology, this means days, if not weeks, hunched over a circular sectioning saw and buffing wheel.

What are they doing using equipment more appropriate for a jewelry store? Cutting and polishing fish ear stones, of course.

These ear stones, or otoliths, are small disks of calcium carbonate that grow on either side of a fish’s brain. Much like the inner ear in humans, otoliths help fish hear, sense vibrations, and maintain balance and orientation. While certainly an essential little piece of anatomy for the fish, otoliths are nearly as essential to fisheries researchers. Continue reading

6th Annual Trout Lake Open House – August 5th!

BOULDER JUNCTION, WI – The UW-Madison Center for Limnology will host its 6th annual open house at the Trout Lake Research Station on Friday, August 5th.


Visitors on the pier watch researchers haul in a Fyke net at the Trout Lake Open House.

From 1 to 5pm, visitors will get a first-hand look at what research is going on at the station this summer, as well as meet the scientists and students conducting it.

Visitors will have the chance to ride out on pontoon boats for a “research cruise” on Trout Lake, meet some of the fish that call Wisconsin’s northern lakes home, learn to tell invasive species from natives, and talk with scientists about the state of Wisconsin lakes and our role in keeping them healthy for future generations.

Freshwater bryozoan

Freshwater bryozoan

There will be aquatic-themed crafts for kids, an art exhibition of material produced by the station’s annual “Artists in Residence,” and, of course, free Babcock Dairy ice cream brought up from the University of Wisconsin’s Madison campus!

The event is free and open to visitors of all ages.

Scientists at the Center for Limnology conduct research all over the world, exchanging knowledge and helping to solve global environmental problems. We hope you’ll join us at Trout Lake Station, where researchers are doing world-class research on Wisconsin lakes.

Trout Lake Station is located at 10810 Hwy N. (between Hwy 51 and Hwy M). For more information, call 715-356-9494.

Notes from the Northwoods: Putting Aquatic Plant IQ to the Test

This summer, Anna Krieg, an undergraduate at Arizona State University, will spend a few months in a much wetter habitat as the CFL’s summer outreach intern at our Trout Lake Station. These are her Notes from the Northwoods:

Susan Knight points out the features of an aquatic plant during the small group rotations. Photo: Anna Krieg

Susan Knight points out the features of an aquatic plant during the small group rotations. Photo: Anna Krieg

by Anna Krieg – On June 28th, 25 people climbed into 6 boats and set off to identify plants on Tomahawk Lake in northern Wisconsin. It was a beautiful day, sunny and calm, and it was time to put everything we’d learned that day to the test. How much did we know about aquatic plants?

From June 28th-30th, aquatic plant identification workshops were held at the Kemp Natural Resource Station, part of the UW-Madison’s College of Agricultural and Life Sciences (CALS) and located just outside Minocqua. Employees from Wisconsin’s Department of Natural Resources mostly populated the classes, but there were also a handful of local residents who just wanted to be able to better identify the plants living in “their” lakes.

Each day started with an introductory PowerPoint session and then everyone was broken up into small groups and began their rotations around the room to learn about all of the aquatic plants. Susan Knight, Interim Direction of UW-Trout Lake Station, spent the week before the plant workshop collecting these samples for the class. Knight is the Center for Limnology’s “plant guru,” and has spent much of her career getting to know the flora of northern Wisconsin lakes. She can stand for hours on end at our annual open houses, just holding court on everything from the invasive Eurasian water milfoil to native carnivorous bladderworts. She has even shared some aquatic plants stories on WXPR public radio.

Continue reading

Notes from the Northwoods: Electrofishing on Allequash Lake

This summer, Anna Krieg, an undergraduate at Arizona State University, will spend a few months in a much wetter habitat as the CFL’s summer outreach intern at our Trout Lake Station. Enjoy her Notes from the Northwoods:

by Anna Krieg – Just as the sun is setting over the trees at Trout Lake Station, Martin, Ellen, Amien, and Jim all meet by the massive electroshock boat and drive out to the lake where they will be electrofishing tonight.

Martin Perales and Ellen Albright plan their root for the night's electrofishing as Jim Miazga looks on. Photo: Anna Krieg

Martin Perales and Ellen Albright plan their route for the night’s electrofishing as Jim Miazga looks on. Photo: Anna Krieg

Electrofishing is a common scientific survey method used to sample fish populations to determine abundance, density, and species composition. A boat, dangling long tendrils into the surface of a freshwater system, uses an on board generator to apply electric current to the water to collect fish. The electric field created does not kill the fish, but temporarily stuns them. The technique allows the fish to be scooped up and handled with less stress and injury sustained than if they were pulled thrashing into the boat. Martin operates the generator and maneuvers the boat skillfully near the edges of the lake where fish tend to hang out and, especially, where predators tend to follow prey toward shore when the sun goes down.

Ellen and Amien stand at the front of the boat with giant nets ready to catch any fish floating to the surface. Jim stands behind to empty the nets into a pool, where the fish will be stored until they can be measured and weighed. Tonight the goal is to measure and weigh as many fish as possible in four separate locations on Allequash Lake.

Amien Paust measures the length of a fish caught during electrofishing. Photo: Anna Krieg

Amien Paust measures the length of a fish caught during electrofishing while another fish waits in the holding tank. Photo: Anna Krieg

This was my first time witnessing electrofishing in action. I was surprised not only by the amount, but also the variety of fish caught. Each run through our four locations yielded dozens of fish from little minnows to walleye to bluegill to large and smallmouth bass. As each fish was weighed and measured, I noticed everyone falling into their role.

Amien, who is still learning how to identify the fish that live in the Northern Lakes region, would measure the fish and call out his best guess as to what it was. Martin would write down the measurements and weights, while double-checking Amien’s identification. Ellen weighed the fish and released them safely back into the water. Jim surveyed the scene, offering his expert fish identification knowledge whenever everyone was stumped. I was lucky enough to sit back and watch, learning from everyone else as they explained things like the different markers of fish, the time of year different species spawned, and the number and type of spines.

As an added bonus, we couldn’t have picked a more beautiful night to be on the water. It was cold and clear and we had millions of stars overhead to keep us company.

Our Next ‘Science on Tap’ Could Change Your Life: May 4th

By now you’ve heard all about our amazing science cafe series, Science on Tap-Minocqua, at the Minocqua Brewing Company on the first Wednesday of each month.

UW-Madison microbiologist, Monica Turner answers questions about the "microbes all around us." Photo: A. Hinterthuer

UW-Madison microbiologist, Trina McMahon answers questions about the “microbes all around us.” Photo: A. Hinterthuer

In addition to the big crowds and good beer, the event is a chance to take part in a discussion and ask questions about some awesome, enlightening topics. In just the past few months, we’ve heard about the creation and conservation of our national parks, the wonderful world of Wisconsin fishes and the microbes all around us.

But, next Wednesday, May 4th, we’ll offer something a little different – something that’s not just good for the mind, but the body and soul as well.

Robert McGrath, director of counseling and consultation at University Health Services. ©UW-Madison University Communications Photo by: Bryce Richter

Robert McGrath.
©UW-Madison University Communications
Photo: Bryce Richter

Dr. Robert McGrath, a UW-Madison distinguished psychologist emeritus and former coordinator of UW Mind-Body Wellness Services will give a talk titled “Thriving at any age: guidelines for living a healthy, happy life.”

McGrath will explain an emerging discipline called “positive psychology,” which focuses on how focusing on gratitude and a healthy lifestyle can increase happiness and set us on a path to thrive. Much of the change in one’s happiness is due less to life events, he says, than to “the nature of your primary relationships, your social relationships, your lifestyle and life goals.”

You can join us as we review ten ways to improve your health, happiness and overall well-being. If you’re in or near Minocqua, stop on by the Minocqua Brewing Company for dinner (we can vouch for the wild rice burger!) and then join us for the conversation at 6:30pm. If you’re not in town, you can always watch LIVE online (or at the Minocqua Public Library) and even ask questions from your computer – we promise we’ll pass them along.

And, as always, if you miss the live show, check out our growing video archive – featuring both full-length talks and short 5-10 minute “highlight” videos on the Science on Tap YouTube Channel.

Questions about the event? Call 715-356-9494 or e-mail hinterthuer(at)wisc(dot)edu.

Open House Recap: Ice Cream, Boat Rides & a Thunderstorm

Trout Lake Station’s 5th Annual Open House and Ice Cream Social was humming along Friday, July 31st. With an hour to go, 332 people had toured the station, getting a look at everything from seed traps, to freshwater bryozoans, to this crazy contraption we call FLAMe.

Freshwater bryozoan

Freshwater bryozoan

It was an outstanding day to do a little science communication and outreach in the Northwoods. We’d nearly exhausted our 7 (yes, seven!) tubs of Babcock Dairy ice cream and and we were only 10 visitors away from breaking our all-time attendance record when, well,  the weather rolled in.

StormVisitors dashed for their cars or huddled under our carport to let it blow over, leaving the record intact for at least another year. In the meantime, here’s a slideshow of what it’s like when we open our doors to the public – enjoy!

Trout Lake Station’s 5th Annual Open House!

Visitors check out stations under the watchful eyes of Bucky at the Trout Lake open house.

Visitors check out stations under the watchful eyes of Bucky at the Trout Lake open house.

It’s that time of year again – as July gives way to August, we’re spiffing up our research station and ordering tubs of Babcock ice cream for our annual open house and ice cream social.

If you’ll be in the Minocqua area next Friday, July 31st, come on by between 1-5pm and board a boat, take a tour, create some crafts, stump a scientist and, of course, enjoy free UW-Madison Babcock dairy ice cream.

Still not convinced? Here’s a slideshow of past open houses to show you what you’re missing!

So come join us – Friday, July 31st from 1-5PM. We’re at 3110 Trout Lake Station Drive (off of County Road N, between Hwy 51 and County Road M).

See you there!


Notes from the Northwoods: Can Native Bugs Take Out Invasive Plants?

by AnnaKay Kruger

UW-Madison undergraduate Joe Bevington rakes the bottom of Manson Lake for Eurasian water milfoil. Photo: AnnaKay Kruger

UW-Madison undergraduate Joe Bevington rakes the bottom of Manson Lake for Eurasian water milfoil. Photo: AnnaKay Kruger

Joe Bevington leans over the side of the boat and eyes the dense weeds in the water below us, watching green, long-feathered arms of Eurasian water milfoil move indolently with the current. The UW-Madison undergraduate wields a long rake that he drags along the lake bottom, twirling tendrils of plant matter around it like spaghetti. He and Jim Miazga, a UW-Stevens Point undergrad, amass piles of slimy milfoil in the bottom of the boat. The damp smells of lake sediment and wet foliage permeate the air.

Susan Knight, the scientist directing this research project, mans the oars as we paddle gently around Manson Lake in pursuit of the milfoil weevil, a small, native beetle that is being monitored for it’s efficiency as a biological control. The bug eats native species of milfoil and, Knight hopes, may have an appetite for the invasive variety. Continue reading

Notes from the Northwoods: Wading to Trip

by AnnaKay Kruger

Michaela Kromrey clips herself into her bulky waders, fitting the straps over her shoulders and sealing herself into their protective rubber lining. We’ve dropped anchor near the shore of Jute Lake, and waves whip the side of the boat vigorously in the high wind. It’s a beautiful day, utterly devoid of cloud cover, but the wind is sharp and swift over the water, forcing us to don our sweatshirts and windbreakers to stave off the chill. Michaela and I, both UW-Madison undergraduates, wait in the boat while Ellen Albright, a student at Minnesota’s Macalester College, wades along the shoreline, dragging a tape-measure behind her.

2015-06-05 10.24.58

Ellen and Michaela wade through the shallows of Jute Lake, looking for submerged logs as part of the Regional Lakes Survey. Photo: AnnaKay Kruger

Ellen paces out fifty meters and drops a small orange buoy into the water. Michaela explains that they’re looking for fallen logs, otherwise known as “coarse woody habitat”. Large logs with many branches are the ideal habitat for juvenile fish populations because they provide protection for fingerlings, or fish that are not yet fully developed but have fins and scales, and are capable of feeding themselves. (Editor’s note: CFL research underscored the importance of coarse woody habitat last year).

The prevalence of suitable habitat for fish populations in inland lakes is one of many variables being investigated in the Regional Lakes Survey out of Trout Lake Field Station. This ongoing study will happen every six years and primarily involves analyzing lake conditions for the purpose of mapping changes that occur over time. Continue reading

Notes from the Northwoods: Heavy Lifting on Sparkling Lake

by AnnaKay Kruger

“Well, that was an adventure!” says Aaron O’Connell, a UW-Plateville undergraduate, looking down at his bare feet as he steps gingerly across the gravel driveway. In one hand he carries his sodden shoes, and like me, he is covered from head-to-toe in lake grime. We have just spent the last two hours helping Tim Meinke launch a buoy into Sparkling Lake off of Highway 51 in Vilas County.

Ben Kranner and Tim Meinke team up to anchor the buoy to the bottom of Sparkling Lake. Photo: AnnaKay Kruger

Ben Kranner and Tim Meinke team up to anchor the buoy to the bottom of Sparkling Lake. Photo: AnnaKay Kruger

The buoy itself is an impressive device—substantial in girth, equipped with everything from weather antennae to a pressure sensor that records rainfall. A large solar panel hangs on one side, and the whole contraption is strung with a variety of complex wiring that is well beyond my expertise.

(Left to right) Ben Kranner, Tim Meinke, Aaron O’Connell, and Mark Gahler tow the buoy out onto Sparkling Lake. Photo: AnnaKay Kruger

(Left to right) Ben Kranner, Tim Meinke, Aaron O’Connell, and Mark Gahler tow the buoy out onto Sparkling Lake. Photo: AnnaKay Kruger

Meinke, a researcher at the Center for Limnology’s Trout Lake Station, is part of the Long-Term Ecological Research project (LTER) and the Global Lake Ecological Observatory Network (GLEON). Sparkling Lake is one of the LTER and GLEON research lakes, so the buoy will spend the summer collecting data on everything from water temperature to wind speed to the amount of oxygen moving in and out of the lake.  But getting that buoy in the water is no small feat, which is why Meinke enlisted Aaron, Ben Kranner, a UW-Madison undergraduate, and the CFL’s IT consultant, Mark Gahler, to the cause.

While they anchored and wired the buoy, I did my best to stay out of the way and document the experience. This proved more difficult than I had anticipated, as the team hauled in various ropes and weights, gradually filling the boat with lake debris and slime (or, as we call it in scientific circles, “muck”) from the bottom. My chance to contribute to the effort came when we had to retrieve a smaller buoy from just under the surface. It was anchored by sixty pounds worth of barbells, which I hoisted into the boat, a feat that proved challenging despite my enthusiasm. With Aaron’s help, we managed to haul the buoy and weights into the boat. I was grimy and out of breath, but proud to have been of service. Continue reading