May 17

The most recent update to the Living Planet Index has revealed that wildlife populations in the tropics have declined by an alarming 61%.

Bengal tiger image

Tiger populations have declined dramatically in recent decades

Trouble in the tropics

The Living Planet Report, produced jointly by the World Wide Fund for Nature (WWF) and the Zoological Society of London (ZSL), assesses the health of the planet’s biodiversity by tracking more than 9,000 populations of animals across the world.

The report obtains its results from the Living Planet Index, an indicator of global biological diversity, which covers more than 2,600 different vertebrate species (birds, mammals, reptiles, amphibians and fish) in both temperate regions and the tropics. The index tracks and analyses changes in the abundance of a variety of species over time, allowing scientists to spot trends in the biodiversity of different areas.

The latest update of the Living Planet Index has found that, globally, wildlife populations have declined by 30% since 1970. While temperate regions have seen an average recovery in wildlife populations of about 30%, the tropics, where the bulk of the world’s biodiversity can be found, have not fared well at all.

The index revealed dramatic declines of 60% in the tropics since 1970, with the worst affected species being those found in tropical lakes and rivers.

Deforestation image

Deforestation for palm oil in Tanjung Puting National Park, Borneo

Causes of decline

The severe declines in the tropics amount to an average biodiversity loss of 1.25% every year since the index baseline was set in 1970. Large-scale human impacts, including deforestation, habitat degradation, overexploitation and pollution, are the principal causes of these dramatic wildlife losses.

The Living Planet Index also examines the impacts in particular regions. For instance, in Central and South America, wildlife populations have dropped by half in the last 38 years. In the Indo-Pacific, where deforestation levels are the highest in the world, a shocking decline of 64% has been observed.

This report is like a planetary check-up and the results indicate we have a very sick planet. Ignoring this diagnosis will have major implications for humanity. We can restore the planet’s health, but only through addressing the root causes, population growth and over-consumption of resources,” said Jonathan Baillie, Conservation Programmes Director with the Zoological Society of London.

Ecological footprints

Maintaining the health of ecosystems and the biodiversity within them is of utmost importance to human wellbeing. Biodiversity provides a number of valuable services, including pollination, carbon capture, food production, and medicines.

Yet analysis from the ‘Global Footprint Network’, which aims to calculate how sustainable our global society is in terms of its ecological footprint, has concluded that humankind is using one-and-a-half times more natural resources than the Earth can sustainably supply.

Amazonian manatee image

Tropical freshwater species have suffered the most dramatic declines

Rio+20

In time for the Rio+20 summit in June, environmentalists are now placing pressure on the world’s leaders to urgently step up the level of protection afforded to our natural resources.

The Rio+20 conference is an opportunity for the world to get serious about the need for development to be made sustainable,” said David Nussbaum, CEO of WWF-UK. “We need to elevate the sense of urgency, and I think this is ultimately not only about our lives but the legacy we leave for future generations.”

The Living Index Report provides some shining examples of recent progress on sustainability, including a project in Pakistan which has helped cotton farmers to dramatically reduce their water, pesticide and fertiliser use, while experiencing no reductions in yield.

Professor Tim Blackburn, Director of ZSL’s Institute of Zoology, likened the latest index figures to a stock market of the natural world:

There would be panic of the FTSE index showed a decline like this,” he said. “Nature is more important than money. Humanity can live without money, but we can’t live without nature and the essential services it provides.

Read more on this story at BBC News – Rio+20 summit leaders ‘must improve nature protection’ and Mongabay.com – Wildlife in the tropics plummets by over 60 percent

Learn more about the Living Planet Index here.

Kathryn Pintus, ARKive Species Text Author