Canada's largest national park – established 95 years ago to protect the last herds of northern bison – is deteriorating and faces significant threats from climate change and industrial development, says an international agency that monitors world heritage sites.

The International Union on the Conservation of Nature (IUCN), which is based in Switzerland and was established in 1948 to encourage conservation and natural diversity, released a World Heritage Outlook report this week that examines the condition of ecologically important sites around the globe.

While the IUCN has some worries about half of Canada's 10 natural world heritage sites, it says Wood Buffalo National Park in northeastern Alberta and southern Northwest Territories poses "significant concerns." The park has deteriorated since the IUCN's 2014 assessment, and in North America, only the Florida Everglades got a worse rating.

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While the park is the site of the recovery of the whooping crane, one of the most spectacular species conservation stories worldwide, the report says, "the combination of climate change and massive hydrological alteration has resulted in ecological, socio-economic and cultural impacts."

Upstream dam construction, including the Site C dam in British Columbia, is changing the processes, navigability and vegetation in the Peace-Athabasca Delta at the southeast corner of the park, the IUCN says, and the expanding Alberta oil sands pose the threat of accidental and long-term discharges of toxic material, including petroleum products.

Moreover, the report says, the federal government's response to the situation at Wood Buffalo has been "inadequate in light of the scale, pace and complexity of the challenges at a time when Parks Canada has recently suffered major budget cuts and lost important science capacity."

The "clear signs" of major environmental change and overarching climate change "would seem to call for a more cautious approach," the IUCN says.

Questions about the report put to the office of Environment Minister Catherine McKenna, who is responsible for Canada's national parks, were redirected to Parks Canada on Wednesday.

Parks Canada said in an e-mail that it welcomed the IUCN report as an important tool for raising awareness of conservation challenges affecting natural world heritage sites, but it does not take into account actions the agency will take in the future to manage Wood Buffalo National Park.

"Canada's national parks do not exist in isolation," the agency said. "In many cases, the conservation challenges stem from outside the national park boundaries, such as climate change. Parks Canada is committed to protecting the ecological integrity of all Canada's national parks, including those that are world heritage sites."

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Alison Ronson, the national director of the parks program for the Canadian Parks and Wilderness Society, said the IUCN report finds that, while many parts of the park are faring well, upstream development is significantly affecting the flow of water in the delta.

"The First Nations and the communities around that area have noticed that the delta is drying, it's disappearing," Ms. Ronson said. "And upstream of the park along the Athabasca River, you have many oil sands developments which are impacting the regulation of the water but also the quality of the water."

In addition, the deterioration is having a huge impact on traditional land use by First Nations, Ms. Ronson said, "which, I would argue, impacts all Canadians because we are in an era now when we really need to be reconciling with our history and reconciling with Indigenous peoples across the country and recognizing that these natural areas are important to them."

Melody Lepine, the director of the Mikisew Cree First Nation, said the people of her community have witnessed the decline of the delta and the resulting loss of important wildlife, including migratory birds, fish, bison, muskrat, beaver and moose.

The IUCN recognizes that the change is significant and "it should be quite embarrassing for Canada to have this sort of review done," Ms. Lepine said. "This is something that the local people have been saying for years ."