Past Winner
2001 Gerhard Herzberg Canada Gold Medal for Science and Engineering

David Schindler

Biology

University of Alberta

The soap with which we wash our dishes and clothes owes much to David Schindler — not for what's in it, but for what's been removed: phosphorous. It's a shining example of how this veteran limnologist's (lake researcher's) groundbreaking scientific work has resulted in major public policy changes for the benefit of the environment and people the world over.

In the 1960s there was extensive scientific debate about what was causing the rapid eutrophication of North American and European lakes. Eutrophication is the overfertilization of lakes with nutrients from human sources such as wastewater and agricultural fertilizers. The most obvious result is rapid and abundant aquatic plant growth and a change in the lake's animal population.

The then 30-something Schindler pioneered the use of whole-lake experiments to determine that phosphorous — rather than carbon, as many researchers then suspected — was the pivotal factor in regulating eutrophication. These whole ecosystem experiments were conducted at the now world-renowned Experimental Lakes Area (ELA) near Kenora in northwestern Ontario, which he founded in 1968 and then directed for 22 years.

His aerial photograph, in a 1974 issue of Science, showing the contrast in water quality between two portions of a dumbbell-shaped lake, one section treated with carbon, nitrogen and phosphorous, and the other with only carbon and nitrogen, was pivotal in the debate regarding the use of phosphorous in detergents.

The result was not only changes in regulations in North America and Europe banning phosphates in detergents and the creation of hundreds of wastewater treatment facilities, but also a new era of whole-ecosystem research.

Schindler subsequently extended his whole-lake research to demonstrate the effects of what became one of the major environmental issues of the 1980s: acid rain. In the mid-1970s, before lake acidification was officially recognized as a problem, he experimentally demonstrated that even mild lake acidification as a result of airborne sulphur oxide deposition resulted in significant losses of biodiversity.

The numerous whole-lake studies he conducted in this period have been credited with directly leading to the control of sulphur oxide emissions throughout the world, and to the Canada-U.S. agreement on the long-range transport of atmospheric pollutants.

His more current research has demonstrated the cumulative impacts on boreal lake life of global warming, acidification and ozone depletion. Using long-term reference data collected at the ELA, he has shown that climate warming and drought have severe and previously unrecognized effects on the physics, chemistry, and biology of lakes.