Environment Counts | Vertebrate population declined by 58% globally over past 40 years :
A new report on the Living Planet by the Zoological Society of London (ZSL) and the World Wildlife Fund (WWF) concludes that on average, monitored species of veterbrate populations declined by 58 per cent globally between 1970 and 2012. The report is based on the Living Planet Index (LPI) which monitors and measures biodiversity abundance levels based on more than 18,000 monitored populations of some 3,700 land, marine and freshwater vertebrate species including mammals, birds, amphibians, fish and reptiles. The LPI database is available online and facilitates both search and controlled contribution of data.
The 2016 report concludes the main threat is habitat loss including logging and deforestation, agriculture, disruption of rivers and other freshwater systems, climate change and poaching. To date, according to the report, there is no sign that this rate of vertebrate decline and consequent reduction in biodiversity has started to decrease.
The report is not, and does not claim to be comprehensive. Criticism of the LPI methodology and data deals with two key deficiencies; gaps in geographic coverage of the data which is , and the concern that monitoring may be disproportionately focused on veterbrate populations that are already declining with consequent insufficient coverage of other populations which in some cases may be increasing. There are approximately 67,000 vertebrate species in the World and the LPI covers some 6% of these.
The LPI report is issued every two years and is based on collected data from peer-reviewed studies, government statistics and surveys collated by conservation groups and NGOs. Reviews of the 2016 report indicate a concensus that the methodology is continually improving along with access to data on more geographically representative populations. Overall, the consensus appears to be that although no data or statistical procedure at present can yield a perfect result, the LPI is the best indicator available at this time.