Dr. John Gunn

Stressed Aquatic Systems - Canada Research Chair


Research Involves

Studying the effects of multiple stressors on aquatic ecosystems of the Boreal Shield ecozone and investigating the potential for recovery of damaged ecosystems.


Research Revelance

Through unique partnerships with industry, government and other universities, this research initiative will contribute to the management and protection of critical freshwater resources on Shield landscapes throughout the world.


Healing the Boreal Shield

The Boreal Shield, with more than one million lakes, is Canada's largest ecozone, containing about 22 percent of our nation's total freshwater surface area. Air pollution, climate change, invasive species, and the expansion of mining, forestry, and hydroelectric development severely threaten the valuable aquatic resources of this area.

Dr. John Gunn, a fisheries biologist, has for the past 25 years studied the effects of acid rain, climate change, and a variety of other environmental factors on coldwater fish communities. As the Canada Research Chair in Stressed Aquatic Systems, he is now leading a team of researchers in the study of the effects of multiple stressors on Shield ecosystems. He is also investigating the recovery processes that operate once stressors are removed. Lakes near Sudbury, Ontario, are particularly important for the recovery studies. Emissions of air pollutants in this area have declined by about 90 percent in recent decades and many aquatic systems are beginning to recover.

Dr. Gunn's research program involves a combination of extensive surveys, long-term monitoring studies, and whole-lake manipulations. For example, a lake de-stratification study simulates the effects of climate warming. Large mechanical mixers are being used to alter the thermal structure of an experimental lake to test the effects of an increase in the volume of the warm surface waters on the community composition and biological production of the system. More than 20 years of background data exist for this lake.

Other research efforts involve the development of new methods for environmental assessment through sampling of fish and benthic invertebrate communities in both streams and lakes. In addition, a detailed modelling study of trace metal impacts on urban and industrial lakes is being conducted.

Watch the video from TEDx Global lessons from a hard-rock mining town