Wildlife in Decline
The populations of Earth’s wild vertebrates (脊椎动物）have declined by 58% over the past four decades, according to the Living Planet Report 2016 published by the World Wildlife Fund.
Climate change and activities such as deforestation and poaching（偷猎）are in large part (21)______(blame) for the decline. If the trend continues, by 2020, the world (22)________(lose) two-thirds of its vertebrate biodiversity. “Sadly, there is no sign yet (23)________ this rate will decrease,” the report says.
“Across land, fresh water and the oceans, human activities are forcing wildlife populations to the edge," says Marco Lambertini, director-general of WWF International.
The Living Planet Report is published every two years. It aims to provide an assessment of the state of the world’s wildlife. The 2016 study included 3700 different species of birds, fish, mammals, amphibians and reptiles around the world. The team collected data from more than 3000 sources, including government statistics and surveys (24) ______ (carry) out by conservation groups. They then analyzed (25) ______ the population sizes had changed over time.
Lambertini said some groups of animals had done worse than others. ''We do see particularly strong declines (26) ______ the freshwater environment. For freshwater species alone, the decline stands at 81% since 1970. This is related to the way that water (27)________(use) and taken out of fre