In late April, 2001, the municipal water supply of North Battleford, Saskatchewan became contaminated with Cryptosporidium, a parasitic protozoan present in the feces of humans and domesticated animals, such as cattle. Dozens of people became ill, and three died from drinking tap water. The probable cause was pollution of the North Saskatchewan River with cattle feces, along with a failure at the municipal water treatment plant that allowed the parasite into the town's water supply. A year earlier, 7 died and 2300 individuals became ill in Walkerton, Ontario from drinking water contaminated with E. coli, an intestinal bacterium in humans and other mammals. Such water crises are no big surprise to David Schindler, one of the world's best-known freshwater ecologists.

Dr. Schindler is the Killam Memorial Professor of Ecology at the University of Alberta. His research centers on the dynamics of freshwater lakes, especially in boreal (far northern) environments. His studies have illuminated numerous threats to aquatic ecosystems, including phosphate pollution, acid precipitation, climate change, and changes in land use, such as deforestation and intensive livestock operations. His many awards include the Canada Gold Medal for Science and Engineering in 2001 and the first Stockholm Water Prize in 1991, considered to be the equivalent of the Nobel Prize for water science. Our interview with David Schindler reinforces one of this book's themes: the connection between science, technology, and society.

How did your interests as an ecologist become focused on freshwater lakes and boreal environments?

Well, the freshwater interest was natural. I grew up in lake country. As for the interest in the boreal, that developed fairly early too. When I was 15, I wanted to go and see Canada. I'd read novels set in northwestern Ontario that were written around the turn of the century. The day I got my driver's license, I headed for Canada with an old German hired man as a chaperone. And I fell in love with the boreal. Never looked back.

Before Alberta, you were a government scientist at The Experimental Lakes Project in northern Ontario, where your research included classic experiments that led to the banning of phosphates in detergents. Tell us about that research.

When the project started in 1968, our mandate was to test water management issues at the level of whole-lake ecosystems. The main objective was the study of eutrophication, the over-fertilization of lakes with mineral nutrients. Eutrophication was causing algal blooms in the St. Lawrence, the Great Lakes, and a lot of European lakes. We started by selecting lakes in north Ontario for our studies and setting up a main campsite there. The big issue at the time was whether phosphorus was the main culprit in eutrophication. Laboratory experiments implicated phosphorus, but my bosses at the time had a hard time convincing politicians and managers to invest millions or billions of dollars in phosphorus management schemes based on these small-scale experiments. Evidence from whole-lake experiments would be more convincing.

Why was there resistance to managing the input of phosphorus into freshwater ecosystems?

One of the big sources of phosphorus in those days was phosphate detergents, and there was a big political lobby defending the use of these phosphate detergents. The companies that produced detergents promoted any types of study that could demonstrate that something other than phosphorus was causing eutrophication of lakes. These companies were pointing the finger at carbon as the main problem.

So how did you test whether it was carbon, phosphorus, or some other nutrient that was causing the eutrophication and algal blooms?

In our best-known experiment, we divided a lake into two basins. We added just carbon and nitrogen to one basin. We included phosphorus along with carbon and nitrogen for the other basin. We got a tremendous algal bloom within weeks after adding phosphorus, but no change with just the carbon and nitrogen. So it was pretty definite evidence that phosphorus was the culprit.

And that was the end of phosphate detergents?

We published our results in Science in 1974, and that pretty well set off a cascade of phosphorus regulations for detergents and sewage effluent. Eastern Canada was looking for a solution to the eutrophication problem, so the response there was quick. But it took 17 years to get all the U.S. states in the Great Lakes region on board. By then, most European countries had also implemented phosphorus restrictions.

That helped solve one problem. What are the most serious current threats to freshwater ecosystems?

There's a whole variety of problems. Acid precipitation is one. Warming of the climate is another. Changes in land use can affect lakes. And easier access to remote lakes is another problem. There are more people with more leisure time. With snowmobiles and four-wheel drive ATVs, people can easily reach lakes that were inaccessible 20 years ago, dragging along all sorts of power equipment. Even our most remote lakes are being exploited as a result. For example, 80% of the walleye fisheries in Alberta have collapsed in the last ten years.

What impact does agriculture have on the water quality in rivers and lakes?

It can be substantial. For example, if you bulldoze a forest to pasture cows on the land, you increase the runoff of nutrients into the water by four or fivefold, at least. And if you plow that land, plant crops, and add fertilizer, you increase the yield of nutrients to the water even more. This is an example of how changes in land use can affect lakes. And now we have these huge, intensive livestock operations—up to 30,000 cattle or 80,000 hogs. The manure has to be dealt with somewhere. Very few of these big livestock operations have sewage treatment. The animals have a lot of the same intestinal microbes that humans have. We would no longer think of discharging raw sewage into a river from a city like Edmonton without treating it. But we do it all the time with intensive livestock operations. We're not handling our fresh water very well. And I think a big problem is that we've tended to look at the water issues, such as land use or acid precipitation, in isolation, when it's usually a combination of factors damaging the ecosystems. And some of the factors affecting one lake may be different from the problems with another lake.

Is there much hope that politicians and government agencies responsible for water quality will be patient enough to base decisions on such detailed evaluation of specific water resources?

Many of these decisions are made by small municipalities, usually in a science vacuum. The tendency is look only at the positive side of the balance sheet. For example, if it looks like an intensive livestock operation or a new housing subdivision is going to make money for local businesses, the project is usually approved without much consideration for water issues or other environmental factors. People who make the decision may look upstream, but they never look downstream!

Can you elaborate on your point that many decisions affecting environmental quality are made in a scientific vacuum?

Most industries have big lobbying arms that make sure that their interests are in the politicians' ears all the time. Scientists don't do that. And politicians seldom think to ask scientists what they think about key issues. There's a lot of marvelous research done by the federal government and university scientists that's never used in environmental decisions. In Canada, the most water-rich country in the world, what happened at Walkerton and North Battleford has people yelling about our water crisis. And all the science we need to prevent or fix those problems has been established for 20 years. It was just ignored. The science ought to be on the table.

The public pressure on politicians must increase when environmental mishaps such as Walkerton and North Battleford make headline news.

Yes, as horrible as those incidents were, they did make people more aware that they can have big problems with fresh water resources, no matter how water-rich a country is. Maybe people are starting to make the connection that these waters are the sewers for the rest of the landscape we're mucking up. And when you have to drink from the sewer, you want to be pretty careful about what goes into it. I think people are going to start demanding some action. But I'm concerned that it may not be the right action. I see all this demand for higher water standards and better technology without much demand for increased protection of watersheds or better training for the people who operate the technology we do have. But I think scientists could influence how the public views the issue.

So, how can ecologists and other scientists have more impact on public policy?

First, I think most scientists should have some sort of course in public communication. I think we should expect scientists to be able to explain to the public any of their research results that bear on critical issues for society. Taxpayers pay most scientists' research budgets and most university salaries. So I think we ought to be giving more back.

It must help a lot when there are some politicians who are actually environmental activists themselves.

Of course. For example, a young, ambitious member of the Canadian Parliament started a series of workshops for politicians called eco-summits. My part is to line up the best science speakers for the topic of each summit. We've had two eco-summits so far, the first on air pollution and the second on water pollution. About a hundred politicians attended the water summit, even though it was held two weeks before Walkerton. In addition to the speeches, there are panel discussions that mix politicians with some of the scientists who are most knowledgeable about the summit issues. We kick off the meeting with a prominent keynote speaker who's a big media draw, and of course politicians don't want to miss a media event. For example, Robert F. Kennedy, Jr. talked about the Riverkeepers program as the keynote speaker for the eco-summit on water.

How can undergraduate biology students participate at such interfaces between science and society?

I think a good way for science students to get involved is to join one or two really good environmental groups. Some of these groups, like politicians, don't have enough connection to science. Biology students can help with that, especially if they learn as much as they can about the basic ecology that underlies environmental issues. Working with ecologists in the biology department is a good way to get involved with the science through research. I've had undergraduates publish papers. I myself had two papers accepted for publication before I started graduate school, one in Science and one in Nature. But I think many students are a little too shy to go and see their professors about working with them. They should take the initiative to operate outside their own little peer groups earlier in life.

©2005 Pearson Education, Inc., publishing as Benjamin Cummings