There is a growing concern about the future of fresh-water resources not just nationally, but across the globe. Limnologists'scientists who primarily study bodies of freshwater with focus on physical and geographical features-have noticed certain trends concerning changes in watersheds as close as Madison's own Yahara system.
UW-Madison Professor Emeritus John Magnuson has devoted much of his life to limnology research throughout the country, from the Pacific tuna of Hawaii to the bluegills of the Atlantic seaboard. Magnuson's long-term research has focused on lake ecological systems, the influence of climate change on inland waters, biogeography and landscape ecology of lake and stream systems, fish ecosystems, and ecological dynamics of bio-diversity and invasion.
What first got you interested in the topic of freshwater resources and limnology?
Well, I think as young kids, a lot of us are just very curious about what's around us. I was no exception, and when we were kids we used to go camping as a family. It was during the [Great] Depression and we'd get shipped up to Grandpa's farm and our aunts would take us fishing. So, a lot of the world which I was exposed to ... included water, and I just got interested in that.
I think I would have been just as happy as a forest ecologist or a grassland ecologist. I was just drawn to the water ... I think part of it was fish and fishing. We would go catch bluegills and things like that, chase bowheads in the creek. But I noticed that if I were to go camping or something, I would go camp at the water's edge or hike up the river ... and I think people in general are drawn to water. In fact, there have been people who have tested [the hypothesis that people are drawn to water]. [Researchers] had a pastoral scene and then the same scene with water in it, a pond or a stream, and people are asked, 'Which do you prefer? Which scene is more attractive to you'? They almost always pick ... ones with water.
For me ... when I was in high school, I didn't know what the options were. I didn't know the word 'limnology' [in high school] ... and so a lot of the opportunities and the really interesting stuff came when I was in college and a graduate student.
In your opinion, why is it important for people to study limnology?
Water is really extremely essential for all of life. I mean, what percentage are you of water? The thoughts are that a lot of major conflicts in human behavior have been around water, and it certainly is still true in our country, especially in the west. But people are thinking that these also can be major sources of conflict of sharing and not sharing water as population goes up, as our consumption goes up ... I can't remember the figure...of what proportion of the world's fresh water is already conscripted for human use, but it's getting to be a large number, a large proportion.
There is still the desire not only to have drinking water, and industrial water and water for irrigation, but you'd like to have water for recreation and water for places to be where there is more of a wilderness. I don't think humans want all water to be captured for the direct purpose of producing products and things that humans need.
There are many concerns about whether water is being used in a sustainable way and whether ... we really have a sustainable interaction with water. In the Madison area, we are drawing down the groundwater. We are mining groundwater here and you tend to think 'maybe that is happening in the Southwest' but it is also happening or occurring right here. We are removing water faster than it is being replaced to the groundwater.
What are the long-term implications of that? We're using water in Wisconsin for irrigation purposes on crops and that reduces the water available for trout streams in that same area. We're not even sure that as a state, let alone a country or a globe ... we have thought through and come up with a sustainable set of policies for the use of water and our interaction with it.
When one sits down on the terrace of Memorial Union and looks out onto Lake Mendota, what are some interesting facts about the lake that they may not know?
Well, they probably know a lot about it. But one of the things is when they look out on the lake ... the immediate thing to take notice of is that the ecosystem that they're looking at is not just the water and the lake, but it is, in fact, an entire watershed. What's happening in that watershed is just as important to how that lake looks and behaves and appears to us as what's happening in the lake.
One of the classic problems of Lake Mendota is that it is overenriched with nutrients that have come from the watershed, and at the present time, the state is involved in a major project to reduce the nonpoint sources of pollution in this watershed. So, when they look at the lake, to understand the lake and the changes in the lake ... the most important single thing is that they need to be able to think about the watershed that the lake is in and how activities on the watershed like urban development ... influence that interaction between the lake and the water.
You tend to look at lakes as standing water, in contrast to rivers, but if you look out on the lake, it's pretty clear that the water's not standing. There [are] waves and currents, and all sorts of things are happening out there. Let's just give you a couple examples.
One example is if you look out on the lake on certain windy days, when the wind is coming ashore, you will see these foam streaks that will run out on the deeper water on the surface. Those are caused by a very complex circulation that we call Langmuir spirals and the water is beneath the surface rotating in sort of cylindrical packages that are beneath the surface, and where those foam streaks are is a convergence. The water is coming together in a sink and you are left with a foam streak.
If you walk up to the lakeshore on a day like that, you will see a foam line running parallel to the shore, and maybe in the fall you'll see not only a foam line but you'll see all sorts of leaves floating there. What happens about 10 or 15 feet offshore, unless it's really wavy, is the water sinks and all the floaty material, the leaves, the foam, is left in a foam line along the shore.
Sometimes we have people say that that foam line runs all the way out into University Bay and there must be a pollutant source. What it really is when people come to us and say 'Where is all that coming from'? is from material that is floating on the surface that comes and remains in that band just a little distance from the shore as the water starts to sink and go back offshore.
What effect does the city of Madison being situated so closely to Lake Mendota have on the lake?
There are several major effects that we might think of. The first one, again, is to think of the city of Madison as part of the lake's watershed. So, of the water that lands on the city of Madison, some of it goes into Lake Mendota, and of course some of it goes into Wingra and Lake Monona as well. You've got rooftops, you've got garages, you've got driveways and you've got streets, and in the streets you've got openings to storm sewers and the storm sewers are essentially an underground river that runs directly to the lake.
Now, when water fell on the top of University Heights about 150 years ago, it had likely seeped into the soil and maybe formed a small surface creek, but when it lands in these areas today or the Madison campus area, it runs in very flashy streams, our streets. Then it goes into these underground rivers and into the lake before you know it.
Another less well known effect that the urban area has on the lake is ... that if the shoreline is developed, if there are houses for example, around the shoreline, you will notice that there is something missing. If you instead [paddle in a canoe] through University Bay and out around picnic point, it is very abundant, and what it is, is human beings over time have just been unwilling to let a dead tree sit in the water. If you stand at the limnology lab and look east towards the Union, there are no dead trees or any structure in the water. If you look west, you see the whole area is topsy turvy, full of logs and stuff like that.
Well, not surprisingly, if you are a fisher and look down along the complex structure of the fallen logs and to the west, you'd say that's a good place to go fishing. If you look towards the Union you might say that's pretty barren looking, there's no place for fish to hide. Well, it turns out that fish pay attention to those things ... experience has shown that you are more likely to catch fish out on the shoreline and these natural shorelines.
Do you believe that the lakes have become cleaner since the development of the sewage plant?
Well the lakes certainly are cleaner... especially Monona, which received a very large dose of only partially treated human sewage during the wars, but we've started using fertilizers more. So, we apply fertilizers more in the last decade than we did 50 years ago, and so while we've cleaned up some of the obvious urban sewage kind of things, we have increased the amount of nutrients on the landscape ... while one thing is better, other things are getting worse. My own personal view is that the lake is getting a little bit better.
What have been the highlights of your career thus far?
I have worked at the University of Wisconsin [as] an assistant, associate and full professor, and now I am an emeritus professor. I have been here since 1967 so a lot of my career has been right here, and Wisconsin has been a very large part of me, and this university which I adore. So, perhaps one of the biggest highlights of my career is being able to spend 30 years here at the university and interact with the students, my colleagues. It's a very diverse faculty. In a community where people are interested in learning and finding out new things, it's been a very exciting 30 years.
... Before I came here, I worked in Hawaii on tuna fish in the central pacific and that was really a very interesting experience for me as well. The tunas are amazing animals, they swim all the time. They can't stop swimming or they fall to the bottom of the ocean or suffocate. ...
I've had the opportunity to serve on a number of committees for the National Academy of Sciences and National Research Council. I've really enjoyed those because these committees have the task very often in a controversial area of trying to come up with a level playing field for the status of science on a particular question.
What is the research in which you are involved, the major focus and what significant findings have you come across?
The last 20 years, up until I retired, I was responsible for what is called the Long Term Ecological Research Program on North Temperate Lakes here in Wisconsin.
About 20 years ago, ecologists were sort of frustrated in trying to understand the world that they were working with because most of the grants at the National Science Foundation and elsewhere were for two or three years. But many of the things that were causing the world to change around us were happening on a longer time scale. So without studying and trying to observe the world at these longer time scales, we were not able to do a very good job of figuring out what was going on.
What I've been doing in the last 20 years is looking at the long-term dynamics of long-term change and variability of these systems ... within Wisconsin especially, and globally.
How many people take part in your research and how were they chosen to work on this project?
People really self-select. I'm not out there running up and down the sidewalks grabbing students. They select to take part, we don't. There are a number of criteria that people use, such as intelligence and motivation, that they are bright and sharp, and thinking about what's going on. The students that drift up to the point of senior thesis are motivated. You select basically for intellectual skills ... and choose courses based on this. There are a whole bunch of words to describe [the people who take part in research] such as creative, quantitative ... have to be good with numbers, highly motivated, driven and bright.
What do you believe is the future of water resources either in this region of the country or throughout the world?
There are two very strong drivers in our future that should make any of us concerned. The increase of population, increase of per capita consumption of resources, whether water or iron or fuel or space to build houses ... this puts increased stress on all of our natural resources, especially freshwater resources.
There really is a challenge ahead of us. In some parts of the world there are more changes than in others. There is a problem, there are concerns and you can't be passive. Friends of the Lake Wingra Watershed is a nongovernmental organization where people that live in the watershed have a concern for the lake, of maintaining quality and improving quality.
Our own watersheds have both the problems of more people and individuals using more resources per capita. People are motivated, people are doing things to try to make things better.
