A United Nations agency has issued a warning about the environmental health of Canada's largest national park.

In a report released Friday, UNESCO says northern Alberta's Wood Buffalo National Park is threatened by energy development, hydro dams and poor management. It warns that unless management of the area improves, the park will be added to the list of World Heritage Sites in Danger.

The report acknowledges that the overall condition of the vast park — bigger than the Netherlands — remains good. But it concludes there's no guarantee of that continuing.

'Governments and industry ... unwilling'

"There is long-standing, conceivable and consistent evidence of severe environmental and human health concerns based on both western science and local and indigenous knowledge," the report says.

"The concerns coincide with the absence of effective and independent mechanisms to analyze and address these concerns at an adequate scale."

A map of B.C. Hydro's proposed Site C dam project (B.C. Hydro) UNESCO inspectors visited the park in September and October. They came at the urging of First Nations, who have long expressed concern about the cumulative impacts on the Peace-Athabasca Delta of hydro projects in British Columbia, oilsands development in Alberta and climate change, which is already changing the landscape.

Members of the Mikisew Cree First Nation say they can no longer get to large parts of their traditional territory because water levels have been declining for more than a generation, starting with construction of the Bennet Dam in the 1960s.

The park is being affected by upstream energy development, the report says.

UNESCO says evidence suggests the oilsands are depositing contaminants in the air, water and land. It says toxins such as mercury are showing up in the food web via bird eggs and fish.

"Governments and industry seem to be unwilling to adequately monitor or accept these claims."

'Uncertain at the very best'

UNESCO's report includes 17 recommendations. They include suggestions to work more closely with First Nations, conduct studies on water flow and to improve monitoring.

"The mission fully agrees with most observers that continuation of the development approach of the last decades renders the future of (the park) uncertain at the very best."

Wood Buffalo National Park comprises 45,000 square kilometres that straddle the boundary between Alberta and the Northwest Territories. The park covers grasslands, wetlands and boreal forests laced with numerous rivers, creeks, lakes and ponds.

It is home to the world's only breeding ground for endangered whooping cranes as well as to the largest herd of free-ranging wood buffalo left anywhere. It is also the summer habitat and breeding ground for billions of boreal songbirds whose migration routes spread throughout the continent.

It became a World Heritage Site in 1983. Shifting it to the endangered site list would make it one of only two such sites in North America and put it in company with others threatened by civil war and social breakdown.