Biodiversity

With construction and operation of hydro facilities come changes to the different birds, animals, fish and plants populating an area. Dams can reduce biodiversity by making spawning habitat inaccessible to some fish species. Nesting, forage and cover along rivers and streams can be temporarily or permanently lost. Large reservoirs can block the traditional migration of animals along or across rivers.

These changes result in unsuitable habitat for some species. But in some cases, hydro plants and reservoirs can help wildlife habitat, supporting fish populations, especially those attracted to slower-moving waters, and providing resting and feeding points for geese and other migratory birds and waterfowl. Reservoirs can increase the shoreline of an original lake or river, expanding wildlife habitat for some animal species. Industry studies show that animals such as caribou seek out reservoirs in northern Quebec for feeding on banks and islands in the winter months.

In the initial years of their development, projects modify wildlife habitat. Hydro companies strive to reduce these impacts by careful planning and operation of facilities. For example, in Quebec, some hydro dams have been built on river sites not accessible to migratory fish.

The industry also implements measures to enhance wildlife habitat, including:

• providing fish ladders
• rebuilding fish spawning habitat
• stocking streams and lakes with fish
• planting trees and grasses along shorelines
• creating wildlife preserves near reservoirs

To better understand industry’s impact on wildlife and their habitat, hydro companies fund wildlife research projects by government and conservation organizations.