Two prominent water scientists say a debate over Canada's largest national park has become politicized and industrial development is being blamed for changes it didn't cause.
Brent Wolfe of Wilfrid Laurier University and Roland Hall from the University of Waterloo say B.C. Hydro's Bennett Dam on the Peace River has had only a marginal effect on northern Alberta's Wood Buffalo National Park.
After 20 years of research and nearly two dozen published papers, they conclude climate change has been drying out the world's second-largest freshwater delta for more than a century.
And that there may be nothing anyone can do about it.
"What our research shows is that this landscape is overwhelmingly influenced by natural processes," says Hall. "You're going to end up wasting a lot of effort."
Their conclusions are disputed by the author of a report done for the federal government, as well as by another leading researcher.
Wolfe and Hall criticize the 561-page study that was done in response to concerns the park's environment has deteriorated, which potentially threatens its status as a UNESCO World Heritage Site.
The study concluded that 15 out of 17 measures of environmental health are declining in the area, mostly because of lower river levels and fewer floods to replenish lakes. It said industry and dams, as well as climate change and natural cycles, are behind the problem.
Wolfe and Hall say sediment cores in area lakes show that the Wood Buffalo region has been drying out since the early 1900s.
"All of our evidence suggests that drying began in the early 20th century," Wolfe says. "We also have evidence that the flood frequency has been declining.
"This has led us to conclude that the main cause of drying is long-term climate change."
The two say the federal study ignores their findings because they are politically inconvenient.
"Society is familiar with attempts by large corporations to obscure the debate with misinformation to stifle credible evidence of their environmental footprint championed by scientists and environmentalists," they write in a document released to The Canadian Press.
"But we have less experience when the situation is reversed — when environmental NGOs, aboriginal organizations and government agencies ignore scientific evidence that runs counter to what they perceive."
David Schindler, a retired University of Alberta ecologist who has extensively studied Wood Buffalo, says there's little doubt that the dam has changed flood patterns on the Peace River.
"Hydro dams are designed to damp high flows and hold back water for low flow periods," he said in an email.
Don Gorber, who wrote the report for the federal government, says Wolfe and Hall's research was consulted. He says the dam does play a role in changes to the park, but adds that his study agrees that climate change is a major factor.
Gorber says what's important is trying to decide how to preserve Wood Buffalo's environment and the livelihood of the First Nations who depend on it.
"We're not denying the fact for the past 100 years there's been a decrease (in water)," he says. "I'm hoping that these people will help try to find a solution as opposed to criticizing one side or the other."
Parks Canada is developing plans to address concerns.
Wolfe and Hall say there may be no solutions to be found.
Deltas change, they say, and perhaps should be allowed to.
"The kind of viewpoint that's being forwarded is that to maintain this UNESCO World Heritage Site it has to be held in this state that existed the year before the dam," Wolfe says.
"This is leading towards a call for more water in the delta. Where are you going to get that water from if it's not flowing down those rivers in the volume that it used to?
"It could lead to a lot of expensive restoration projects that will have limited or no success."
— Follow @row1960 on Twitter
Bob Weber, The Canadian Press