Two-Thirds of Wild Animal Populations Could Be in Decline by 2020

Around the world, more than two-thirds of wildlife populations could be in decline by the year 2020 because of human activity on the planet, says a new report from the World Wildlife Fund (WWF) and the Zoological Society of London, a conservation charity.

The Living Planet Report, which the WWF puts out every two years, says that populations of vertebrates (including mammals, birds, fish, amphibians and reptiles) dropped by 58 percent between 1970 and 2012. Of course, quantifying biodiversity loss around the planet is no easy task, and there are long-raging debates about how much species loss spells disaster. The picture will get even worse if we don’t take steps now, the WWF says.

“Within one generation, we’ve seen drastic declines in global wildlife populations,” James Snider, vice-president of science, research and innovation at WWF-Canada, told me. “One of the more troubling facts is that it seems, based on reporting [every two years], that the decline is worsening.” The 2014 report showed a 52 percent decline over the same period, he noted. “Based on that, we expect that by 2020, If no significant action is taken, it could be as much as two-thirds of populations that have declined since the 1970s.”

A black-footed ferret in Saskatchewan. According to WWF-Canada, habitat loss is the biggest threat to biodiversity on land here. Image: Troy Fleece/WWF-Canada

The report looks at three of Earth’s biomes: ocean, freshwater, and land. The freshwater species that were included in the research appear to be particularly hard-hit, showing an 81 percent decline between 1970 and 2012. (Land-based creatures were at 38 percent, and ocean dwellers at 36 percent.) For example, the report cites an alarming decline in river dolphins, like Irrawaddy dolphins, which live in coastal parts of Southeast Asia, and are dying off partly because they’re being accidentally entangled in fishing nets.

In Canada, as of May, 739 wildlife species were at risk, WWF-Canada says.

It’s important to note that the WWF report isn’t suggesting two-thirds of all species will be extinct, or even endangered, by 2020—just that their populations may be squeezed. Instead of giving a census of species around the world, this report tracks how populations change in size. Shrinking numbers can spell disaster for a species under pressure. “When you have smaller populations, they’re more vulnerable to extinction,” Snider noted.

Read More: Is There Really Such Thing as a ‘Safe’ Limit for Biodiversity Loss?

Cataloguing biodiversity loss is a critically important job, but it’s not without huge challenges and uncertainties. To put together this report, researchers contacted agencies, institutions and academics around the world, Snider said. One big hurdle is the potential danger of comparing apples to oranges: different agencies and experts will report and track species loss differently, while other species and regions are data-deficient.

According to Snider, the science team went to great lengths to “harmonize the data,” in order to sidestep this problem as best they could, and the methods have been peer reviewed. (WWF’s original Living Planet Index was published in 2005.)

Caribou migrating across the tundra. Caribous were once one of the most widespread species in Canada, according to WWF-Canada, but some herds are now down by more than 95 percent. Image: Bryan and Cherry Alexander/WWF-Canada

Then there’s the thorny matter of determining how much biodiversity loss is too much, before it veers the planet towards catastrophe. This new report relies on the idea of “Planetary Boundaries” for biodiversity, which suggest there’s a “safe” limit for biodiversity loss, within which the functioning of ecosystems can continue relatively unaffected.

Earlier this year, a study in Science found that biodiversity had dropped below these “safe” thresholds across an estimated 58 percent of the world’s land surface. (This study is cited in WWF’s new report.) But, as Motherboard previously reported, the idea of a boundary is controversial, and is subject to a lot of uncertainty, at least according to some scientists.

All of this aside, species are indisputably dying because of habitat loss, overexploitation, pollution, poaching, and climate change. African elephants’ numbers have fallen by around 111,000 since 2006, according to the WWF report, hitting 415,000 today. One-third of sharks, rays, and skates are thought to be threatened with extinction because of overfishing. Orca whales are now prowling the warming waters of the Arctic, as Snider told me, where they were very rare until recently—a top predator that will reshape the food chain.

The WWF report points to renewable energy, reduced food waste, and business models that prioritize climate change as some solutions. They can’t come quickly enough.

“The underlying ecological systems that support wildlife populations, also support humans,” Snider pointed out. “We need to take mindful action to reverse the trend in favour of wildlife and biodiversity, and also for ourselves.”

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