In this International Year of Biodiversity, a multinational group of zoologists, biologists and ecologists has assessed 24 biodiversity indicators and found that global declines in these key indicators are either fluctuating or continuing.
The Convention on Biological Diversity (CBD), adopted in 2002, was a commitment to achieve significant reductions in biological diversity loss by 2010. With the recognition that biodiversity plays a significant role in human well-being and quality of life measurements, the convention’s goal was subsequently included in the United Nations Millennium Development Goals.
Publishing the results of their integrative study in the May 28, 2010 edition of Science Magazine (Global Biodiversity: Indicators of Recent Declines, Butchart et al), the group’s aggregate analysis “suggests that biodiversity has continued to decline over the past four decades, with most state (of biodiversity) indicators showing negative trends.”
A new, aggregate study of key biological diversity indicators shows the rate of decline in genes, species loss, population loss, and ecosystem services is continuing.
Previous analyses of gene, species and population losses have been published, but the group’s study is the first empirical analysis to integrate a broad spectrum of biodiversity indicators. In an effort to determine whether the CBD goal is being met, the team calculated “aggregate indices” reflecting the state of biodiversity (in a given region/area), the biodiversity “pressure” (impacting factors), environmental/ecological policy and management, and the state of “ecosystem services” (that people derive benefit from). The starting year for calculating (positive/negative) biodiversity trends was 1970.
More specifically, the analysis found there to be continued declines in population trends of vertebrates, habitat-specialized birds, shore birds (worldwide), the extent of forested land, mangroves, seagrass beds, and the condition of coral reefs.
The study also found that “aggregate species’ extinction risk (i.e., biodiversity loss at the species level) has accelerated.” This finding included data from the Red List Index–compiled annually by the International Union for the Conservation of Nature (IUCN)–showing the rate of change (in species loss) to be in a negative trend.
Most of the indicators reflecting “pressures on biodiversity” show increasing trends (since 1970), and include: increases in “aggregate human consumption of ecological assets”, increases in the deposition of reactive nitrogen (typically through the over-use of synthetic fertilizers), the number of alien (invading) species (in Europe), the proportion of fish stocks that are over-harvested, and the impact of climate change on (European) bird populations.
Watch this 5 minute video focusing on the Convention on Biological Diversity’s 2010 goal (article continues below):
Although sufficient data on habitat fragmenting (a critical factor in many invertebrate life-cycles) was not available for this analysis, the group asserts that this too is probably increasing, given existing data on Atlantic Forest fragments (80% of these fragments are <0.5 km²) and large river systems (59% are “moderately or strongly fragmented by dams and reservoirs”).
According to the authors, there have been some improvements in land management policies, and modest increases in protected areas as well as the total area of sustainably-managed forests under stewardship, and also, the proportion of countries signing international agreements (or passing legislation) to limit the spread and impact of alien species. However, this improvement rate is also slowing.
Although there has been some local, positive improvements in stemming or reversing biodiversity loss (primarily in protected areas), globally, the findings of this aggregate analysis show that the rate of increase in biodiversity loss is stable.
The authors conclude: “…efforts to address the loss of biodiversity need to be substantially strengthened by reversing detrimental policies, fully integrating biodiversity into broad-scale land-use planning, incorporating its economic value adequately into decision making, and sufficiently targeting, funding and implementing policies that tackle biodiversity loss…”
The group also advises that sustained investment in global biodiversity monitoring is imperative to tracking and improving these policy responses.