London, May 16 : The latest data on the global biodiversity of vertebrates shows that it has fallen by almost one-third in the last 35 years.
According to a report in New Scientist, the data, known as Living Planet Index (LPI), is based on a wide range of population datasets, such as commercial data on fish stocks and projects such as the Pan-European Common Bird Monitoring scheme.
It follows trends in nearly 4,000 populations of 1,477 vertebrate species and is said to reflect the impact humans have on the planet.
The new figures show that between 1970 and 2005, the global LPI has fallen by 27%, which suggests that the world will fail to meet the target of reducing the rate of biodiversity loss set by the 2002 Convention on Biological Diversity.
"Governments have signally failed to deliver on their biodiversity commitments, and biodiversity declines are continuing," said Jonathan Loh, a researcher at the Institute of Zoology and the editor of the report.
The report determined that ground-living vertebrates have declined by 25%, with most of the slump occurring since 1980.
Marine species held fairly steady until the late 1990s before falling sharply to give an overall drop of 28%. Freshwater species have decreased by 25%, primarily since the late 1980s.
According to Loh, the most dramatic declines have been observed in the tropics. Tropical ground-living species have seen an average population drop of 46%, while their temperate cousins have shown no overall change.
"Freshwater vertebrates show different trends in different regions, leading to no obvious signal," said Loh. European and North American populations show no overall change, but Asian-Pacific populations have declined steeply since the late 1980s, he added.
In the world's oceans, northern vertebrate populations have held fairly steady over the entire period, but may have entered a downward trend since 1990. By contrast, southern populations have fallen precipitously, although because less data is collected there the trend is less certain.