Securing the web of life

This week's update shows that of the 63,837 species assessed, 19,817 are threatened with extinction, including 41% of amphibians, 33% of reef building corals, 25% of mammals, 13% of birds, and 30% of conifers. The IUCN Red List is a critical indicator of the health of the world’s biodiversity. The latest update included assessments for many freshwater molluscs and cuttlefish, that were created, in collaboration with international species experts, by the ZSL’s Indicators and Assessments Unit

“Sustainability is a matter of life and death for people on the planet,” says Julia Marton-Lefèvre, Director General, IUCN (International Union for Conservation of Nature). “A sustainable future cannot be achieved without conserving biological diversity—animal and plant species, their habitats and their genes—not only for nature itself, but also for all 7 billion people who depend on it. The latest IUCN Red List is a clarion call to world leaders gathering in Rio to secure the web of life on this planet.”

“A green economy is one that values all species, whether they have market value or not,” says Professor Jonathan Baillie, Director of Conservation Programmes at the Zoological Society of London (ZSL). “To stop the rapid increase of threatened species and ecosystems the Rio + 20 Earth Summit
must succeed in laying the foundation of a new development path that values all life.”

While most people in wealthy countries depend primarily on domesticated species for their dietary needs, millions of other people are dependent on wild species. Freshwater ecosystems are under substantial pressure from expanding human populations and exploitation of water resources. An important food source, freshwater fish are facing threats from unsustainable fishing practices and habitat destruction caused by pollution and the construction of dams. A quarter of the world’s inland fisheries are located on the African continent, yet 27% of freshwater fish in Africa are threatened including the Oreochromis karongae, an extremely important source of food in the Lake Malawi region that has been severely overfished. Further studies are being carried out in other regions and in the latest IUCN Red List update the Mekong Herring (Tenualosa thibaudeaui), an important commercial fish endemic to the lower Mekong River in the Indo-Burma region, has been listed as Vulnerable as a result of overfishing and habitat degradation.

In some parts of the world up to 90% of coastal populations obtain much of their food and earn their primary income through fishing; yet over-fishing has reduced some commercial fish stocks by over 90%. 36% of skates and rays are threatened with extinction including the commercially valuable Leopard Ray (Himantura leoparda), which is listed as Vulnerable due to extensive habitat degradation and heavy fishing pressures. More than 275 million people are dependent on coral reefs for food, coastal protection and livelihoods. Globally, coral reef fisheries are worth US$ 6.8 billion annually. Overfishing affects 55% of the world’s reefs and according to The IUCN Red List, 18% of groupers, an economically important family of large reef fish, are threatened. Coral reefs must be managed sustainably to ensure they continue to provide the essential food that millions of people rely on as a source of protein.

Production of at least one third of the world’s food, including 87 of the 113 leading food crops, depends on pollination carried out by insects, bats and birds. This ecosystem service is worth over US$ 200 billion per year. According to the IUCN Red List 16% of Europe’s endemic butterflies are threatened. Bats, which are also important pollinators, are also at risk with 18% threatened globally. The latest IUCN Red List update shows that four members of the hummingbird family, which is known for its pollination services, are now at greater risk of extinction with the Pink-throated Brilliant (Heliodoxa gularis) listed as Vulnerable. In addition to their important pollination roles, bats and birds also aid in controlling insect populations that may otherwise destroy economically important agricultural plants.

Invasive alien species are one of the leading and most rapidly growing threats to food security, human and animal health and biodiversity. A recent analysis of IUCN Red List data highlighted invasive alien species as the fifth most severe threat to amphibians, and the third most severe threat to birds and mammals. Together with climate change, they have become one of the most difficult threats to reverse. For example, Water Hyacinth (Eichnornia crassipes) is an aquatic plant native to the Amazon basin, but in Africa its rapid spread poses a significant threat to water supplies and the use of inland waters for fishing or transportation. The economic impacts may be as much as US$ 100 million annually across all of Africa. Solutions incorporating awareness and prevention measures, as well as early warning and rapid response systems that include containment, control and eradication programmes, need to be implemented on both a regional and global scale in order to reduce the negative effects of alien species.

The latest IUCN Red List shows that 10% of snakes endemic to China and South East Asia are threatened with extinction. Snakes are used in traditional medicines and anti-venom serum, as food, and as a source of income from the sale of skins. Nearly 43% of the endemic snake species in South East Asia in the Endangered and Vulnerable categories are threatened by unsustainable use. The world’s largest venomous snake, the King Cobra (Ophiophagus hannah), is listed as Vulnerable due to loss of habitat and over-exploitation for medicinal purposes. The Burmese Python (Python bivittatus), best-known in the West as an invasive species in the Florida Everglades, is also listed as Vulnerable in its native range, with trade and over-exploitation for food and skins, especially in China and Vietnam, being the main threats to the species. Despite its designation as a protected species in China, populations there show no evidence of recovery, and illegal harvesting continues.

In some countries, medicinal plants and animals form the basis of most of the medicinal drugs people use, and even in technologically-advanced countries like the USA, half of the 100 most-prescribed drugs originate from wild species. Amphibians play a vital role in the search for new medicines as important chemical compounds can be found on the skin of many frogs. Yet 41% of amphibian species are threatened with extinction, including the recently described frog, Anodonthyla hutchisoni, from Madagascar, which is now considered Endangered.

Important services supplied by species include improvement and control of air quality by plants and trees. A mature leafy tree produces as much oxygen in a season as 10 people inhale in a year. They clean the soil, act as carbon sinks, and clean the air. Bivalve molluscs and many wetland plants carry out water filtration services to provide clean water, whilst snails help control algae. In Africa 42% of all freshwater molluscs are globally threatened and in Europe 68% of endemic freshwater molluscs are globally threatened by habitat loss, pollution and the development of dams.

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