The LPI, which measures trends in thousands of populations of mammals, birds, reptiles, amphibians and fish across the globe shows a decline of 58 per cent between 1970 and 2012. If current trends continue, the decline could reach two-thirds by 2020.
The 2016 LPI draws on records of population size over time for:
- 4,658 monitored populations of 1,678 terrestrial species.
- 3,324 monitored populations of 881 freshwater species.
- 6,170 monitored populations of 1,353 marine species.
Threat type information is available for about a third of declining populations. The main threats to these populations are habitat loss and degradation, for example conversion of natural areas for agricultural expansion, followed by overexploitation of species, such as unsustainable fishing.
Populations of terrestrial species declined by 38 per cent between 1970 and 2012. The majority of Earth’s land area is now modified by humans, which has had a large impact on biodiversity.
However, designated protected areas cover 15.4 per cent of the Earth’s land surface, which is likely to have slowed the decline in the terrestrial index compared to freshwater and marine indices.
The LPI for freshwater species shows the greatest decline, falling 81 per cent between 1970 and 2012. The main threats are habitat loss and degradation for example through direct impacts from dams and unsustainable water extractions, followed by overexploitation.
Marine species populations declined 36 per cent between 1970 and 2012. The majority of the decline in the marine LPI occurred between 1970 and the late 1980s, after which the trend stabilizes.
Overfishing is the most common threat, and while some fisheries are now showing recovery because of stronger management measures, the majority of the fish stocks that contribute most to global fish catch are now either fully fished or overfished.