A spectacular North American wilderness forms the backdrop to a canoeist on a Canadian Rocky Mountains lake. This extremely beautiful part of Canada enjoys protection by a vast national parks system that draws millions of visitors every summer season. The nature-loving man in the canoe is no doubt enjoying the beautiful scenery around him, and yet he has not come to Jasper National Park as a tourist.

David W. Schindler, a professor of ecology based at the University of Alberta, Edmonton, loads samples of aquatic organisms into his canoe with the help of a bag-net. Another instrument chews into the clay sediment, bringing it up to the surface, while in a plastic bottle he collects water from the different strata of the lake.

Schindler’s field samples provide him with facts about the abundance of certain species, biological diversity, levels of acidity, and concentrations of nutrients, toxic trace metals and chlorinated organic compounds, to mention but a few of the variables he wishes to study.

David Schindler has been doing field research of this kind in the mountain lakes and watersheds of Canada for more than three decades. It all began back in 1968, when he set up the Experimental Lakes Project for Canada’s Department of Fisheries and Oceans in Ontario. He headed the research carried out under the auspices of this project for twenty-two years, until 1989. As a limnologist and ecologist, his aim was not to study individual parameters in isolation, but all of them simultaneously, in order to construct an image of the entire lake as an integrated ecosystem.

Schindler’s results, particularly from the late 1970s and early 1980s, were to be instrumental in convincing regulators in the United States and Canada to introduce stricter controls on phosphates and acidifying pollutants such as sulphur dioxide. Measurements of eutrophication levels showed quite clearly that atmospheric nitrogen and carbon have important effects in maintaining phosphorus limitation in lakes, as well as promoting blooms of blue-green algae.

A famous photograph of a Canadian lake drew attention to the effects of phosphorus, and played an important part in generating public support for tackling the growing problem of eutrophication, which is the overload of nutrients in aquatic systems and one of the most serious environmental threats facing freshwater bodies and semi-enclosed seas like the Baltic Sea. That photograph has since been reproduced hundreds of times, for students, scientists and the general public. Equally important was the research that showed that the effects of acidification can work their way through the food chain, and once again photographic documentation was a crucial factor in shaping public opinion. Many of the results of the project have proved to be highly relevant in the context of sustainable development worldwide.

Since Dr. Schindler received his Prize in 1991, he has initiated new programmes to study the fates and effects of organic pollutants and climate warming in mountain and boreal lakes. Schindler has received a number of additional awards for his work. In 1998, he and Professor Malin Falkenmark shared the Volvo Environment Prize; in particular, he was cited for his “insights in the processes of eutrophication and acidification of freshwater and of ways to counteract these processes Dr. Schindler has also received the Gerhard Herzberg Gold Medal for Science and Engineering, Canada’s highest scientific honour, and he has been elected to the U.S. National Academy of Sciences, the Royal Society of London, and the Royal Swedish Academy of Engineering Sciences.