A new analysis looking at the long-term trends of more than 900 species of wildlife in Canada has found that half of them have seen their populations decline, including several species already listed as threatened or endangered.

The Living Planet Report Canada, released on Thursday by World Wildlife Fund Canada, paints a bleak picture for wildlife in a country that is home to a quarter of the earth’s wetlands, 8,500 rivers and more than 2m freshwater lakes.

During the past four decades, human activity – whether industrial development, farming, forestry or the expansion of urban areas – as well as climate change, pollution and overfishing have helped shrink the populations of 451 species, representing half of the 903 monitored species in the country.

“I think for many Canadians, it’s somewhat of a surprise,” said James Snider of WWF Canada and the lead author of the report. “Canada is this vast nation with huge wilderness areas, at times we assume that wildlife here is doing OK.”

The list of species in decline ranges from the woodland caribou, who grace the country’s 25¢ coin but have seen their habitat shrink from logging, mining and gas development, to the several species of whale that live off Canada’s three coasts.

The report found that for species with diminishing populations, the average loss was 83% of their population. “That’s a really striking number,” said Snider.

The report – billed by the conservation group as the most comprehensive synthesis of Canadian wildlife population trends to date – was compiled using more than 400 sources of data on species population.

Beluga whales swim in Arctic waters. Despite being listed as threatened, their habitats was not legally protected until 2016. Photograph: Andrey Nekasov/Ecoscene/Barcroft

Scientists looked at more than 3,700 populations of vertebrates, including 106 specials of mammals, hundreds of fish and bird species and dozens of 46 amphibians and reptiles, during a period that stretched from 1970 to 2014.

Wide gaps remain in regions such as the Arctic, where a lack of historical information prevented researchers from drawing conclusive results. It’s a critical omission, said Snider.

“Climate change is being witnessed in the Arctic at a rate really not seen elsewhere in the world. We need to be effectively monitoring today the status of wildlife populations so that we can understand the impacts of climate change on a lot of really unique and important species in the Canadian north.”

Climate change is being witnessed in the Arctic at a rate really not seen elsewhere in the world

Of the 903 monitored species – representing about half of the known vertebrates in Canada – 407 species showed an increase in population, while 45 remained stable.

Success stories included the once struggling raptors – such as Cooper’s hawks and peregrine falcons – whose species have seen their numbers swell an average of 88% in recent decades, thanks to the reduced use and outright bans of pesticides such as DDT. Their rebound hints at the turnaround that is possible, said Snider. “So when we as society decide to take action and elevate the concern of wildlife, we are able to make real change.”

Researchers, however, found that federal legislation – one of the country’s primary tools aimed at protecting wildlife at risk – had failed to stem the decline of many species. The report looked at 64 species protected by federal legislation and found their populations diminished by an average of 2.7% per year since 2002, when federal legislation was adopted to protect species at risk, as compared to an annual decline of 1.7% between 1970 and 2002.

A peregrine falcon in the Bay of Fundy, Canada. With its rebounding population, the bird is one of Canada’s success stories. Photograph: Mircea Costina / Rex Features

“According to researchers, the federal Species at Risk Act (Sara) has faltered in its mission to protect Canada’s most beleaguered wildlife,” the report noted.

A number of peer-reviewed journal articles have documented shortcomings in the federal government’s efforts to curb the loss of wildlife, from delays in recognising critical habitat to the years-long process of creating recovery strategies.

Snider pointed to the beluga whale population in the St Lawrence estuary off Quebec as a potent example of these issues. After the population was listed as threatened in 2005, the creation of a recovery strategy dragged on for seven years.

It took until 2016 for the beluga’s habitat to be legally protected – more than a decade after the species was initially listed as threatened. The delays were not without consequence, as this year saw the status of the St Lawrence beluga upgraded to endangered.

“This is a clear message that we need to be doing more to prevent the decline of wildlife,” said Snider. “If the rate of decline of wildlife continues as it is today, I do think we face the risk of beginning to lose species from Canada.”