Importance

Addressing biodiversity loss requires knowledge about biodiversity, assessments of the effectiveness of policy and management decisions – usually through adaptive management – and decision making in accordance with the national biodiversity strategy, relevant biodiversity targets and other sustainable development objectives. Because of the complexity of biodiversity, incomplete taxonomic knowledge and high cost of biodiversity assessments and monitoring programmes, monitoring will typically rely on a small number of indicators, for which data are available. Biodiversity indicators are information tools, summarizing data on complex environmental issues to indicate the overall status and trends of biodiversity. They can be used to assess national performance and to signal key issues to be addressed through policy interventions and other actions. The development of indicators is, therefore, important for monitoring the status and trends of biological diversity and, in turn, feeding back information on ways to continually improve the effectiveness of biodiversity management programmes. Biodiversity indicators, when used to assess national or global trends, build a bridge between the fields of policy-making and science. Policy makers set the targets and measurable objectives, while scientists determine relevant variables of biodiversity, monitor current state and develop models to make projections of future biodiversity status. Once they are selected, indicators give direction to monitoring and research programmes.

Status, trends and causes of biodiversity loss

The second edition of Global Biodiversity Outlook demonstrates that biodiversity is being lost at all levels, for example:

• Deforestation, mainly through conversion of forests to agricultural land, continues at an alarmingly high rate. The loss of primary forest since 2000 has been estimated at 6 million hectares annually. Coastal and marine ecosystems have been heavily impacted by human activities, with degradation leading to a reduced coverage of kelp forests, seagrasses and corals. In the Caribbean, average hard coral cover declined from about 50% to 10% in the last three decades. Some 35% of mangroves have been lost in the last two decades in countries for which adequate data are available.
• Trends of some 3,000 wild populations of species show a consistent decline in average species abundance of about 40% between 1970 and 2000; inland water species declined by 50%, while marine and terrestrial species both declined by around 30%. Studies of amphibians globally, African mammals, birds in agricultural lands, British butterflies, Caribbean and Indo-Pacific corals, and commonly harvested fish species show declines in the majority of species assessed.
• More species are becoming threatened with extinction. The status of bird species show a continuing deterioration across all biomes over the last two decades and preliminary findings for other major groups, such as amphibians and mammals, indicate that the situation is likely worse than for birds. Between 12% and 52% of species within well-studied higher taxa are threatened with extinction.

In addition, forests and other natural habitats are increasingly fragmented, affecting their ability to maintain biodiversity and deliver ecosystem goods and services. Within the 292 large river systems assessed, for instance, only 12% of river-basin area was unaffected by dam-based impacts. The intensification of fishing has led to the decline in large high-value fishes, such as tuna, cod, sea bass and swordfish, which are high up in the food chain. In the North Atlantic, the number of large fish has declined by two-thirds in the last 50 years. The threats to biodiversity are generally increasing. Humans contribute more reactive nitrogen to ecosystems globally than do all natural processes combined. The rate and risk of alien species introductions have increased significantly in the recent past, and will continue to rise as a result of increased travel, trade and tourism. Overall, unsustainable consumption continues, as indicated by our growing global ecological footprint. The global demand for resources now exceeds the biological capacity of the Earth to renew these resources by some 20%. On the positive side, the number and area of protected areas is increasing, although most ecoregions fall well short of the target to protect 10% of their surface. Marine ecosystems in particular are poorly represented, with approximately 0.6% of the ocean’s surface area and about 1.4% of the coastal shelf areas protected.

Source: http://www.cbd.int/indicators/intro.shtml accessed 29 October 2008. 

Drawing on a range of information sources, including National Reports, biodiversity indicators information, scientific literature, and a study on assessing biodiversity scenarios for the future, the third edition of the Global Biodiversity Outlook (GBO3) summarizes the latest data on status and trends of biodiversity and draws conclusions for the future strategy of the Convention. The GBO3 can be accessed at http://gbo3.cbd.int/.

The GBO3 was launched in 10 May 2010 in a number of cities worldwide namely: Alexandria, Bonn, Brasilia, Chamonix, London, Manama, Montreal, New York, Nairobi, Panama, and Tokyo. A number of resources related to GBO3 have been made available at http://gbo3.cbd.int/resources.aspx.

Source: CBD, Global Biodiversity Outlook accessed on 15 July 2010.