March 17, 2011

Canada’s Boreal Is World’s Largest Water Source

A new report by the Pew Environment Group has revealed that Canada's boreal forest, the world's largest on-land carbon storehouse, contains more freshwater than any other ecosystem, totaling more than 197 million acres of surface freshwater.

As water scarcity and pollution continues to be a major topic, especially as the United Nations celebrates the International Year of Forests and World Water Day, scientists are calling boreal protection a top global priority.

Canada must limit large-scale industrial activity in its boreal forest, to preserve millions of lakes and rivers critical to forming Arctic sea ice, the Pew report states.

"When you look at a color-coded map of the world's (unspoiled) freshwater reserves (marked in blue), it's just shocking to see all the blue in Canada," the study's lead author Jeffrey Wells told AFP.

Canada's boreal forest provides a vital fortification against global loss of biodiversity, irreplaceable food and cultural benefits to rural communities, and also slows the impact of global warming. These ecosystem services have an estimated $700 billion annual value.

Twenty-five percent of the world's wetlands are contained within Canada's boreal and it has more surface water than any other continental-scale landmass. Half of the world's lakes larger than 0.6 sq. miles in size and five of the 50 largest rivers in the world are located in the boreal, as well as the single largest remaining unpolluted fresh water body: Great Bear Lake.

The extensive river system of the boreal serves as a last safe haven for many of the world's migratory fish, including half of the North Atlantic salmon populations.

The waters of the boreal also influence the world's climate. Wetlands and peatlands store as much as 160 billion tons of carbon, more than 25 years worth of man-made emissions. The delta of the Mackenzie River alone stores nearly 45 billion tons. The boreal fresh water rivers are critical to the Arctic and other northern seas for them to form sea ice, which cools the atmosphere and provides the basis for much of Arctic marine biodiversity.

University of Alberta Ecologist David Schindler -- recipient of the first Stockholm Water Prize (1991) and a member of the International Boreal Conservation Science Panel (IBCSP), which reviewed the report -- said that the world needs to act quickly to safeguard natural water resources. "Enacting sound conservation policy to protect Canada's free-flowing waters and wetlands in the boreal is not just a local issue; it is one of global importance," he said in a statement.

Impacts from large-scale industrial activities have put an increasing strain on Canada's boreal forest. Global demand for resources from the boreal is rising, with more than half of total exports of forest products, oil, natural gas and hydropower going to the United States.

Lakes have been drained to access minerals or to dispose of mine waste. Erosion from logging is increasing amounts of silt flowing into rivers, which can reduce regional precipitation on a large scale. Construction of hydroelectric dams has also destroyed or degraded wetlands in the boreal.

"At a time when clean water supplies are disappearing, the vast reserves in Canada's boreal are increasingly important to protect," said Steve Kallick, director of the Pew Environment Group's International Boreal Conservation Campaign. "Canadian provinces and First Nations have already made major strides defending the integrity of the vast lakes, rivers and wetlands in the forest, but they need to do more to guarantee that Canada's water stays pure and abundant, watershed by watershed."

The Pew Environment Group worked with First Nations, federal, provincial and territorial governments, and conservation groups to protect the boreal forest. As a result of their work, 185 million acres of boreal have been set aside, including key wetland and river systems. The total represents more than 12 percent of the boreal forest's 1.2 billion acres.

But the Pew report concludes that governments should protect entire wetland ecosystems by preserving at least half of Canada's boreal forest. It also demands that "sustainable" development in the rest of the northern forest must be abided by.

"In conservation, so much of the discussion is centered on scarcity and loss," said Dr. Stuart Pimm, Doris Duke Chair of Conservation Ecology at Duke University and IBCSP member.

"It is imperative that the world recognize and protect the fresh water that is left. Canada has an extraordinary opportunity that does not exist anywhere else in the world to keep its aquatic ecosystems intact and to create a positive ripple effect on the land, animals, birds and people who depend on these resources," Pimm added.

Most of the boreal rivers and lakes in Eastern Canada drain into the Hudson and James bays before water is carried northward to the Labrador Current and then flows south into the North Atlantic.

The Mackenzie River influences the strength and movement of major currents in Western Canada, including the Beaufort Gyre and the Transpolar Drift, which carries cold, less-salty polar waters south into the deepwater North Atlantic Conveyor and back to the tropics.

The Yukon River flows into the Bering Sea and contributes to the extensive sea ice of the Bering Sea before continuing north, eventually contributing to the North Pacific Current that rushes through the Bering Strait into the Arctic Ocean.

Seasonal sea ice would fade and temperatures around the world would quickly rise if these flows were at all reduced or restricted. If left unchecked, warming could lead to decreased precipitation in the boreal forest, resulting in drying lakes and ponds to the point where they would no longer have outflow, the study said.

The analysis is the first compilation of decades of research on the boreal water reserves from more than 200 scientific studies, government reports and other sources.


Image 1: Oscar Lake and surrounding mountains in the boreal forest of Canada's Northwest Territories. Cerdit: The Pew Environment Group

Image 2: Ecosystem services provided by Canada's boreal, such as climate control, food, and water filtration, are estimated to be more than $700 billion annually.


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