According to a new study by the wildlife group WWF, the Zoological Society of London and other nonprofits, the global animal wildlife population is dropping at a dramatic rate. The comprehensive meta-study undertook an analysis of thousands of vertebrate species, and determined that overall wildlife populations decreased by 52% between 1970 and 2010.

Wildlife Declining Much More Rapidly Than Expected: Study

The study published Tuesday, September 30th noted that the wildlife population decline was seen in all environments, in rivers and lakes, on land and in the oceans, and is clearly related to rapidly increasing habitat destruction, and over-hunting and fishing. Although climate change is widely believed to be a factor, the specific contribution to animal population declines is more difficult to measure.

New report highlights dramatic decline in wildlife

An earlier WWF report focusing on animal populations published in 2012 concluded that wildlife populations were down by 28% during the four-decade period. The new WWF report has 15% more data than the earlier study. The latest study is also more representative of tropical species and uses an improved methodology.

Data from the study showed that the most rapid wildlife declines were seen in rivers and other fresh water systems, where overall wildlife numbers are down by 76% since 1970. Terrestrial and marine populations were each down by 39% during the period.

Moreover, biodiversity is declining in almost all areas of the planet, but the decrease in biodiversity is the greatest in the tropics.

Latin America saw the largest drop in wildlife numbers, with overall populations of mammals, birds, reptiles, amphibians and fish down by 83%. The Asia-Pacific region also saw major drops in animal populations.

Living Planet Index

The conclusions in the latest study are based on the WWF’s “Living Planet Index,” which is designed to  measure biodiversity based on trends in 10,000 populations encompassing more than 3,000 animal species.

The WWF created its Living Planet Index back in1998. The index tracks a large number of animal populations much like a stock market index tracks the value of stocks in a specific industry. The key data points for the LPI  are population size, density or a measure of abundance over a length of time.