Assistant Professor Glynnis Hood of the University of Alberta-Camrose said beavers might be considered pests, but their removal from wetlands to accommodate industrial, urban and agricultural demands should be avoided.

"Removal of beaver should be considered an environmental disturbance on par with in-filling, peat mining and industrial water extraction," Hood said.

In examining how beavers influenced some of Alberta's wetlands in Elk Island National Park, Hood and Professor Suzanne Bayley discovered the presence of beavers and their dams increased by up to nine times the presence of open water.

"In times of drought, they may be one of the most effective ways to mitigate wetland loss," Hood said. "Some people believe climate is driving everything, but the presence of beaver has a dramatic effect on the availability of open water in an area. Beaver are helping to keep water in areas that would otherwise be dry."

The study recently appeared in the online edition of the journal Biological Conservation.