Since the days the first humans migrated into the ecozone near the end of the last ice age, the Boreal Shield’s sweeping network of rivers and lakes has served as a crucial transportation route, a foundation for rich domestic fisheries, and a natural wellspring of fur-bearing mammals. More recently these waters have come to be known for outdoor recreation and the development of hydro-electric power.

Much of the freshwater resources of the Boreal Shield are relatively untouched by human activity. Others have been widely exploited. Flow alteration and mercury contamination from hydro dams and associated river diversions, acidification from mine tailings and smelter emissions, and sedimentation and stream disruptions from extensive logging activities are the consequences of industrial development.

As for the boreal forest, fire suppression, insect control, clear-cutting and single-species tree farming are widespread. These practices may, over the long term, reduce the diversity of both plant and animal species and increase the forest’s vulnerability to disease.

Many Shield lakes and soils are extremely sensitive to changes in pH. Acid rain from local sources and from the long-range transport of airborne pollutants has already taken an ominous toll. It may be weakening the general vigour and growth rate of trees, as well as of aquatic species, in sensitive areas.

Mining, forestry, hydro generation and fisheries are all important contributors to the Canadian economy. With the help of environmentally responsible regulations and policies, they will be able to continue well into the future. Beyond its economic opportunities, the Boreal Shield continues to provide more intangible but priceless gifts -- pure air and water, food and habitat for wildlife, and recreational, aesthetic and spiritual benefits.