FOR IMMEDIATE RELEASE: Contact Carl Watras, 715-356-9494, email@example.com
BOULDER JUNCTION, WI – For at least the last seventy years, lakes and aquifers in northern Wisconsin have followed the same pattern – after higher than average peaks, water levels spend about ten years on a downward trend before abruptly spiking up again, only to repeat the decade-long fall back to low-water conditions. The cycle holds true for aquifers and seepage lakes in northern Wisconsin, the gigantic freshwater body formed by Lakes Michigan and Huron, and every lake in between.
FOR IMMEDIATE RELEASE: In attempts to predict what climate change will mean for life in lakes, scientists have mainly focused on two things: the temperature of the water and the amount of oxygen dissolved in it. But a new study from University of Wisconsin researchers is speaking for the trees – specifically, the dead ones that have toppled into a lake’s near-shore waters.
For fish in northern Wisconsin lakes, at least, these trees can be the difference between pastures of plenty and the Hunger Games.
Under ‘normal’ water-level situations, says Jereme Gaeta, a post-doctoral researcher at the UW-Madison’s Center for Limnology and lead author of the study, trees in the water provide “coarse woody habitat.” Not only do they offer a refuge for fishes that would otherwise be lunch, they also provide food for those fishes – serving as structure for algae to grow on and aquatic insects to live.
Last Saturday: I wake up. I’m at the bottom of a four foot deep hole in the snow. I have large scrapes and bruises up and down my side. My left arm is sore and doesn’t have full range of motion. There is a Nalgene filled with my own urine sitting next to me. My back aches. I take a picture.
Readers of this blog may already be aware that Pete McIntyre and a handful of his staff and students are undertaking a big research project in Tanzania. Now a new interactive website is in the works that will let folks at home follow along as the team plies the waters of Africa’s gigantic Lake Tanganyika.
The following promo for the site was just released. Stay tuned for updates!
“Okay, now we’re going to do a little role playing,” the moderator announced to the room. “We need a customer and a shopkeeper, would anyone like to read a script?”
After a little coercion, two reluctant thespians assumed their roles and launched into an exchange, trading lines like “How much for that brass dish, sir?” and “You drive a hard bargain, young lady.”
The exercise is designed to help multiple stakeholders learn how to achieve what might be called “win/win” resolutions and is taken from the book “Getting to Yes: Negotiating Agreement Without Giving In.”
For hundreds of years people have collected data on lakes. Ice on and ice off dates are probably the oldest data, but water temperature, water clarity, animal and plant species and abundance have also been recorded for a long time. Scientists usually collect data to answer a specific question for which they are summarized, analyzed, graphed, and interpreted. Sometimes the conclusions are published, other times they’re used in management. Once the question is answered satisfactorily, most original data are lost (if not actively thrown away during clean up).
In recent years, however, it’s become obvious that documenting the changes going on in our climate, lakes and other ecosystems requires having data available from a long period of time. Luckily, some researchers, agencies and citizens did not clean up and kept their data – in notebooks, on index cards, in boxes or drawers, on desks, and now on computers. Here at the Center for Limnology we are lucky that data collected by early limnologists like Edward Birge and Chauncy Juday were not discarded, but are still available to us and our research. Many cardboard boxes full of handwritten numbers on index cards are stored in the University Archives and have recently been fully digitized, a fancy way of saying “hand-typed into a computer database.”
They are now part of our data archive, which is where a lot of data go that are collected by some projects at the Center for Limnology. A data archive is not so different from a regular archive or a museum. All items (datasets in this case) are cataloged and described with who collected them, when, where and how they were collected, for what purpose etc. In other words, data are curated like museums specimens.
I like to think of the CFL archive as a museum for data. The only difference is that we don’t have them in cabinets or in glass display cases, but they can still be pulled out and used to answer new research questions – questions that weren’t and, in some cases, couldn’t have been envisioned when the data were first collected. For example, in the late 1990’s researchers prepared an experiment to combat the rusty crayfish invasion of a northern Wisconsin lake. The crayfish had already been around for more than a decade and long-term datasets, including those of Birge and Juday, as well as the annual samples taken for LTER, were used to set basic parameters of northern lakes, allowing scientists to piece together what the lake looked like pre-invasion and what effects the rusty crayfish had on the ecosystem over time.
The data archive at the Center for Limnology currently houses almost 300 datasets, many of which go back 30 years to when the North Temperate Lakes Long-Term Ecology Research project started to monitor lakes. But there are also data that go back much longer, like Secchi depths for water quality and almost one hundred and fifty years’ worth of ice data. All of this information is becoming more and more valuable as we see the world around us change very rapidly. It helps us interpret the change we see and predict the future with more certainty.
Corinna Gries is a research scientist with the North Temperate Lakes-Long-Term Ecological Research project. Special thanks to UW-Madison Archives for the footage of E.A. Birge.
A recent study authored by our former postdoc and PhD student, Gretchen Hansen, reports that an intensive invasive-species trapping experiment had paid off for Sparkling Lake in northern Wisconsin. Not only did our researchers put a big dent in the rusty crayfish population but, four years later, they’re still being kept in check naturally.
Click on the picture below to launch a slideshow of life in the lake today.
All photos by Gretchen Hansen, Adam Hinterthuer and Lindsey Sargent.
The CFL’s Ellen Hamann, lab manager for Pete McIntyre’s lab, has been back in Africa this summer, helping continue research on Lake Tanganyika. She sent in this note from the field before returning to Madison for fall semester.
By Ellen Hamann
For the past 48 hours, Benja (Ben Kraemer from Pete McIntyre’s lab) and I have been finishing up the ongoing fish excretion component to our Lake Tanganyika project. It’s pretty similar to last year’s endeavor except that it occurs primarily at NIGHT (in year 3, we seem to be finding creative ways to up the proverbial ante…). At this point, we have a pretty good handle on fish peeing rates during the day, but the suspicion is that things probably tail off at night (which is personally true for me, so it may hold true for the fishes as well).
Just to be clear, we’re not interested in peeing for peeing’s sake. As I’ve mentioned before, since Tanganyika is so lacking in nutrients, we suspect the fish themselves facilitate nutrient cycling in the lake (Meaning: algae probably take full advantage of the fact that hundreds of fish pee on them constantly, providing them with nutrients to create biomass that, in turn, feeds the fish) I “heart” cycles.
There’s a fair amount of prep work involved, like filtering 100 liters of water, labeling all the Ziplocs and vials, etc… and the field experience is a bit nuts since a job that was formerly performed by 6 people is now done by 3.
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 –>