Muckraking Mendota: A Brief History of Fish

The fish crew pulls in a gillnet after an overnight set. Photo: E. Hilts

Last week, like every week this summer, I was out on the water looking for stories about Madison’s lakes. But, this time, I had company. One of the cooler summer jobs at the Center for Limnology, is to be a member of “fish crew,” the team of students that spend the summer netting, IDing and taking a general yearly census of the fish in Madison lakes. For a few days, I got to be an honorary member.

The return of fish crew is the beginning of the end of summer. Every year, four student technicians spend five weeks at Trout Lake Station, and then the rest of the summer sampling the Madison Lakes, maintaining a data set on fish populations and diversity that extends back to 1981. With the school year drawing closer, I was glad the most exciting fieldwork that goes on at the Center for Limnology was still ahead. What could be more exhilarating than being out on the lake seeing fish up close? Keep reading –>

Time-Lapse Video: Latest Spring Thaw in 32 Years at Trout Lake

Ever see a scientific chart or graph and wonder what all of those multicolored dots and lines look like in real life? Well you’ve come to the right place! Below is a time-lapse video showing the 2013 spring thaw, or “ice-off” on Trout Lake in northern Wisconsin’s Vilas County. This video captures the latest ice-off in 32 years and marks the previous years’ melts for reference. Big thanks to Tim Meinke for this unique visual take on our historical records!

Trout Ice Off 2013 from Center for Limnology on Vimeo.

Video: 2 Months Breaking Ice in Under 5 Minutes

While this isn’t news directly from the Center for Limnology, it is WAY cool and postdoc, Cayelan Carey’s, recent talk on (and love for) all things phytoplankton inspired us.

Marine scientist/science writer, Cassandra Brooks, is currently on an expedition in Antarctica’s Ross Sea, chasing phytoplankton blooms (literally) around the end of the earth. Funded by the National Science Foundation and aboard the stalwart icebreaker, the Nathaniel B. Palmer, Brooks compiled this time-lapse video of two months at sea. Enjoy.

For more on the expedition, Brooks is blogging about the experience for National Geographic. Maybe yours truly will try re-creating the experience aboard our vessel, the Limnos, during cyanobacteria season on Lake Mendota!

“David Buoy” Ready for Year 6 on Lake Mendota

Early season boaters on Lake Mendota may have noticed a familiar sight out on the water this spring – a bright yellow beacon, bobbing right above the lake’s deepest point.

David Buoy ready to record measurements on  Lake Mendota for the 2013 season. Photo: Luke Winslow

David Buoy ready to record measurements on Lake Mendota for the 2013 season. Photo: Luke Winslow

Meet “David Buoy,” the tireless floating scientific instrument that has plumbed the depths of our fair lake for five years. Luke Winslow, a graduate student in the Hanson Lab at the  Center for Limnology, has been with the buoy since the beginning. Starting the project as an undergrad, Luke has helped fine-tune the instruments collecting data, dealt with random acts of vandalism, and monitored conditions in Mendota. The data collected by the buoy (some available online in real-time) will help researchers here at the CFL better understand what drives the health of Lake Mendota and how human activities affect its waters.

For example, using data in part collected by the buoy on water temperature and plankton communities, scientists at the CFL can now predict in the spring what harmful algal blooms are likely to be like in the summer.

Luke Winslow works to get "David Buoy" installed for a field season with the Wisconsin capitol building in the background.

Luke Winslow works to get “David Buoy” installed for a field season. Photo: Ted Bier

Winslow recently worked with a team of divers and researchers to get David Buoy out onto the lake for 2013. He sent in this write up below: Continue reading

A Look at Our Lakes on Earth Day

Happy Earth Day!

Wisconsin, of course, is where it all began, thanks to former U.S. senator Gaylord Nelson’s vision. As we here at the blog mulled over an appropriate topic for an Earth Day post, we kept seeing local media coverage about Madison’s lakes. And that had us returning to one thought – April rains bring July pains.

Satellite view of phosphorous-driven algal blooms. Phosphorus carried into Lake Mendota via the Yahara River fertilizes algal growth. Photo: UW SSEC and WisconsinView

Satellite view of phosphorous-driven algal blooms. Phosphorus carried into Lake Mendota via the Yahara River fertilizes algal growth. Photo: UW SSEC and WisconsinView

While the entire Midwest has been waiting for spring to finally fight off winter (sorry, Minnesotans) and get some of those May flowers out of the ground, our daily deluges also have a longer-lasting impact. We asked Center for Limnology director, Steve Carpenter to comment on this soggy spring and here was his reply: Continue reading

Road Salt Turns Deep Water into “Low-Sodium Soup”

Before the ice melts off these lakes here in Madison (we will get ice-off this year, right???), we thought we’d share a report from our senior research technician, Ted Bier, who you may have seen out with facilities manager, Dave Harring, drilling holes in the ice around town this winter as they collected data for the Long-Term Ecological Research network.

Ted Bier and Dave Harring take a plankton sample from an ice-covered Lake Mendota.

Ted Bier and Dave Harring take a LTER plankton sample from an ice-covered Lake Mendota. Photo: Adam Hinterthuer

The LTER is a National Science Foundation-backed effort to record ecological change throughout different ecosystems across the U.S. There are a couple dozen LTER research sites, and we here at the CFL run the one concerned with lakes – the North Temperate Lakes research site includes both Madison lakes and a handful up north in Vilas County.

Last month, Ted and Dave were out on Lake Wingra and Ted noticed that Wingra’s deeper waters were quite briny. The culprit, of course, is the salt used melt ice off of our roads during the winter.

Ted (left) and Dave (right) winter sampling on Lake Wingra.

Ted (left) and Dave (right) measuring salinity on Lake Wingra. Photo: Ted Bier

But what does this annual salinization mean for our resident lakes? We asked Ted, and here is his reply:

When salt (sodium chloride) washes into the lakes, it does
not dilute evenly through the whole water column. Water that contains dissolved salt is heavier than fresh water, so it settles in the deepest part of the lake bottom, or “deep hole,” where it forms a lens of salt water many times more concentrated than normal levels.

This is of concern to biologists because most native, aquatic
flora and fauna are not adapted to high saline concentrations. The list of consequences is long, but disruption of osmoregulation is the most severe. In short, salt-water is toxic because it interferes with freshwater organisms’ ability to balance the water concentration in their cells. In salty water, cells expel water, which can cause dehydration.

Small, urban lakes are at greatest risk, because water run-off is high with respect to lake volume. So, it is little surprise that Lake Wingra is our most affected lake in Madison. And the level is not just concerning, in the winter, it approaches levels that could be lethal. Every organism’s tolerance is different, but generally speaking 400 milligrams per liter is bad-news-bears for most critters.

The concentration I found in Lake Wingra was 600 milligrams per liter at the bottom of the deep hole. That is about the same concentration as low-sodium soup. And, in fact, if you taste the water (and I do), it is noticeably salty. Salinity decreases to 150mg/l once you get a meter off the bottom, so many fish can swim into safer water. But, plants and animals living in the muddy bottom are occupying a salinity level that freshwater scientists would predict would put them in a high stress environment.

It’s also important to note that many invasive species are adapted to saltier water. Eurasian water milfoil – a well-known invasive plant – doesn’t mind increased salinity one bit. In fact, the plant frequently inhabits brackish waters in its native habitat, so road salt tips the scales that much more in favor of a plant that already has some native species on the ropes.


It’s important to note that Ted’s not predicting cataclysmic effects from winter road salt in the Madison lakes. Once the ice comes off of Wingra and the lake has its annual turn-over, the salty bottom water will be diluted as it mixes through the water column. Then, as fresher water flows through the system in the warmer months, salinity won’t be a problem for native species.

But, placing any sorts of stressors on native species can make them less able to compete with invasives, more susceptible to disease and have other effects on the ecosystem. Road salt has been shown to be a bigger problem than first believed for aquatic life, one that’s spawned a lot of research on ways to reduce salt use while still keeping roads safe.  The City of Madison has reduced its salt use over the years, switching to sand in an attempt to keep the lakes healthy all year long.

While it has helped, salt is still part of our urban aquatic ecosystem and, next winter, the process will start all over again. For many bottom-dwelling organisms, especially the aquatic invertebrates that Lake Wingra’s fish eat to get them through the winter, the bottom of the lake will be a stressful place to call home.




April 9th Event – Our Freshwater Future: Peril and Promise

Only 2.5% of all the water on earth is freshwater. 70% of that freshwater is frozen into glaciers and snowpacks in mountainous regions, leaving a tiny fraction of all water on earth available for every living thing that needs a drink.

Sunrise over Western Lake Erie. The Great Lakes hold 21% of the world's surface freshwater. Photo: Adam Hinterthuer

Sunrise over Western Lake Erie. The Great Lakes hold 21% of the world’s surface freshwater. Photo: Adam Hinterthuer

How do we protect and preserve this precious resource? Can a future featuring a booming human population also be one in which we are good stewards of one of the most necessary elements of life?

Postel, director of the Global

Postel, director of the Global Water Policy Project and National Geographic Foundation’s Freshwater Fellow.

Addressing big questions like these is all part of Sandra Postel’s job. Postel is the director of the Global Water Policy Project and lectures, writes and consults on global water issues. In 2010, she was appointed the founding Freshwater Fellow of the National Geographic Society, where she serves as lead water expert for the Society’s Freshwater Initiative.

She’s also the author of the books Pillar of Sand: Can the Irrigation Miracle Last? and Last Oasis: Facing Water Scarcity. 



On Tuesday, April 9th at 7:00 p.m., she will be in Madison to give a talk entitled “Our Freshwater Future: Peril and Promise” at the Overture Center for the Arts, Capitol Theater. Continue reading

Changing Climate, Warming Lakes and an “Endangered” Outdoor Experience

Tomorrow evening at the Minocqua Brewing Company, former CFL director, John Magnuson, will team will UW-Madison climate scientist, Ankur Desai, for our science cafe series “Science on Tap-Minocqua.” The topic tomorrow is climate change in Wisconsin. And one thing that will undoubtedly come up is an altered outdoor recreation landscape. Especially in winter.

These lucky visitors in 2007 got to hike on the thick Lake Superior ice to see the "ice caves" that form in winter. The park service hasn't issued a "safe ice" alert, clearing hikes to the caves since 2009. Photo: Damon Panek, NPS

These lucky visitors in 2007 got to hike on the thick Lake Superior ice to see the “ice caves” that form in winter. The park service hasn’t issued a “safe ice” alert clearing hikes to the caves since 2009. Photo: Damon Panek, NPS

Yesterday, an article ran on the news service, Environment & Energy Publishing, about the “endangered” experience of visiting Lake Superior’s ice caves. The story reminded yours truly of last year at this time, when I was shin-deep in slush on Trout Lake photographing Trout Lake Station’s annual LTER Schoolyard event. Times are changing, folks. Keep reading below for a an excellent article on what warmer winters mean to northern Wisconsin and the Apostle Islands. Continue reading

“Science on Tap” a Smashing Success

Even “standing room only” wasn’t enough. As if the lively chatter, hearty laughter and spontaneous rounds of applause weren’t proof, the line of people snaking out the door of the Minocqua Brewing Company‘s Divano Lounge confirmed that interest was alive and thriving in Wisconsin’s Northwoods.

No, it wasn’t a Packers playoff game. It was “Science on Tap.”

Science on Tap participants swarm the Minocqua Brewing Company

Why was this bar hopping? Science, of course. Photo: Adam Hinterthuer

On Wednesday, February 6th, the Center for Limnology, Kemp Natural Resources Station, the Lakeland Badger Chapter of the Wisconsin Alumni Association, the Minocqua Public Library and the brewery  all teamed up to host the first installment of “Science on Tap-Minocqua.” The topic was “Wisconsin’s Northwoods: A Changing Landscape in Changing Times.” Continue reading

LTEArts Goes to Washington: Exploring the Beauty of Science on Wisconsin Lakes

In 2011, researchers at the Center for Limnology’s Northern Temperate Lakes Long Term Ecological Research project teamed up with artists in Wisconsin’s Northwoods to explore a new way of communicating science. They all asked the same question – what happens when six artists and six scientists join in exploring the complexity, beauty and future of northern lakes?

Little Ripple, watercolor, Ann Singsaas - a painting in the original LTEArts exhibition

Little Ripple, watercolor, Ann Singsaas – a painting in the original LTEArts exhibition

The result was “Drawing Water,” a traveling exhibition of painting, quilting, sculpture and poetry that casts an artist’s eye on scientific research being conducted in Wisconsin lakes. Continue reading