Despite Canada's vast wilderness, populations of half its vertebrate species are shrinking, a new World Wildlife Fund report finds. And endangered species like woodland caribou and St. Lawrence beluga whales continue to disappear even after becoming protected by federal laws.

The Living Planet Report Canada, released Thursday morning by the conservation group WWF-Canada, found 451 of 903 mammal, bird, reptile, amphibian and fish species across the country — half the species in the study — declined in number between 1970 and 2014.

James Snider, vice-president for science research and innovation at WWF-Canada and the lead author of the report, said that was a surprise.

We need to act before species get identified as endangered, because it's so hard to turn around populations once they're deteriorated that far. - David Miller, CEO, WWF-Canada

"Frankly, as a Canadian, I think we all pride ourselves in the relative wilderness," he said, "and we almost have an assumption … that most of our wildlife would be doing well."

On average, the species that were declining lost 83 per cent of their Canadian population during the study period.

Mammals declined an average of 43 per cent.

Amphibians and reptiles lost 34 per cent of their populations on average.

Fish populations declined by 20 per cent.

Grassland birds dropped 69 per cent, aerial insectivores (such as swallows and martins) fell 51 per cent, and shorebird populations declined by 43 per cent, even as waterfowl and birds of prey increased.

Declines were seen in species across the country, but grassland species such as bobolinks showed some of the sharpest drops.

A new report from the World Wildlife Fund of Canada has found that Canada's wildlife has suffered a steep decline over the past 40 years 2:31

The report analyzed publicly available population data from places like scientific databases and journals using the Living Planet Index, a peer-reviewed method developed by the London Zoological Society. It's also used by the WWF to create global reports on vertebrate population trends every two years.

Habitat loss, climate change

The report suggests habitat loss due to human activity such as farming — the main problem in the grasslands — forestry, urban and industrial development is a major cause, along with climate change, pollution, invasive species and overfishing.

The report also found that Canada's threatened and endangered species keep declining despite federal legislation designed to protect them and help their populations recover.

In fact, species listed under Canada's Species at Risk Act (SARA) have declined even more quickly on an annual basis since the legislation was adopted 2002.

"I think that's troublesome in terms of whether it's indicative of the relative success of the federal program for the recovery of species at risk," said Snider.

The 87 species in the study protected under the SARA declined by 63 per cent over the research period. Their populations shrank an average of 2.7 per cent per year after SARA was enacted, up from 1.7 per cent a year before 2002.

"According to researchers, the federal Species at Risk Act has faltered in its mission to protect Canada's most beleaguered wildlife," the report says.

Bobolink populations have decreased by 80 per cent since the 1970s. Grassland species such as bobolinks, along with shorebirds and aerial insectivores like swallows showed some of the sharpest declines seen in the report. (May Haga/State of Canada's Birds)

David Miller, president and CEO of WWF Canada, told CBC News: "The lesson we take from this is we need to act before species get identified as endangered, because it's so hard to turn around populations once they're deteriorated that far along the scale."

Delays in protection

One reason species decline despite being protected by SARA is that, in many cases, the government takes a long time to decide whether to accept a scientific recommendation to list a species, and there are further long delays between listing a species and actually taking action, the WWF says.

For example, the woodland caribou was listed as threatened in 2003, but its "recovery strategy" wasn't released until 2012. "During this time, development activities continued to damage key woodland caribou habitat," the report says. It adds that actual action plans to help the woodland caribou recover aren't due from the provinces and territories until the end of 2017.

The WWF's Canadian study, the first since 2007, took two years and cost hundreds of thousands of dollars, Miller said.

Snider said the goal was to look for trends to see how different groups of species, ecosystems and regions of the country were faring across Canada, in part to help the WWF determine where conservation efforts are most urgently needed.

Lake whitefish are among the freshwater fish in the report that saw some of the biggest declines. However, the report noted that there was relatively little population data available for freshwater ecosystems. (Paul Vecsei via Engbretson Underwater Photography/WWF)

The report notes there were some big gaps in the data for regions such as freshwater ecosystems and the Arctic. "As a result, we lack sufficient data to answer key questions about the status of wildlife and to track and evaluate trends over time," it said. It recommends collecting more data to track biodiversity across the country.

The WWF recommends a number of other actions by governments, businesses and the public to help reduce the loss of wildlife such as:

Doing more research on how wildlife are impacted by and responding to climate change.

Doing a better job of implementing SARA, including focusing on protecting ecosystems rather than individual species.

Expanding Canada's network of protected areas.

Philip McLoughlin, a population ecologist at the University of Saskatchewan, studies large mammals in Canada, including woodland caribou in northern Saskatchewan.

We have to quit focusing on writing these obituaries for nature. - Julia Baum, marine biologist

He thinks establishing an index to monitor Canada's wildlife is a "really good idea" that will allow us to look back in 20 or 30 years to see if and how things have improved.

"And being able to have the data and people consciously collecting data for an index like this, I think this bodes well," he said.

He added that the report is "bang on in terms of the challenge we have in such a large country to protect species at risk."

Julia Baum, a marine biologist at the University of Victoria who has just completed a study of population trends among marine fish in Canada, said she'd be interested in seeing the data used in the index. Her analysis shows marine fishes are doing "a lot worse" than they appear to be doing in the report.

The way the report groups species together can obscure important details, as species that are increasing can cancel out those that are declining, she notes.

"On one hand, it's great to have report like this, that gives us this comprehensive, wide-ranging, high-level view of what's the status of wildlife in Canada," said Baum. But she's now more interested in looking for ways to rebuild populations.

"We have to quit focusing on writing these obituaries for nature," she added. "Because what we really need is to start problem solving."