Invasive alien species needs closer attention

View of an alien plant species.


Millions of people are dependent on wild species for their livelihood. 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.

The latest update of the IUCN Red List of Threatened Species™, released on the eve of the UN Conference on Sustainable Development in Rio de Janeiro, Brazil, shows that of the 63,837 species assessed, 19,817 are threatened with extinction, including 41 percent of amphibians, 33 percent of reef building corals, 25 percent of mammals, 13 percent of birds, and 30 percent of conifers. The IUCN Red List is a critical indicator of the health of the world's biodiversity.

Fishing

A quarter of the world's inland fisheries are located on the African continent, yet 27 percent 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.

In some parts of the world up to 90 percent 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 percent percent. 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 percent of the world's reefs and according to The IUCN Red List, 18 percent of groupers, an economically important family of large reef fish, are threatened.

Food security

Crop wild relatives, such as the Critically Endangered Beta patula, a primary wild relative of cultivated beets, are of vital importance for food security and agriculture as they can be used to produce new crop varieties. It is estimated that crop wild relatives contribute more than US$100 billion worldwide towards increased crop yields. Production of at least one third of the world's food, including 87 of the 113 leading food crops, depends on pollination carried out by insects, bats and birds. This ecosystem service is worth over US$ 200 billion per year. According to the IUCN Red List 16 percent of Europe's endemic butterflies are threatened. Bats, which are also important pollinators, are also at risk with 18 percent threatened globally.

Invasive alien species

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.

Reptiles

The latest IUCN Red List shows that 10 percent 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 percent 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.

Medicinal plants and animals

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 percent of amphibian species are threatened with extinction, including the recently described frog, Anodonthyla hutchisoni, from Madagascar, which is now considered Endangered. More than 70,000 different plant species are used in traditional and modern medicine. Today's IUCN Red List update includes a number of South East Asian plants which are used for food and medicine.

In several cases the over-exploitation combined with loss of habitat due to deforestation and other threats has resulted in species being listed in a threatened category. Two relatives of turmeric – Curcuma candida and Curcuma rhabdota, Candy Cane Ginger, are both listed as Vulnerable, and the Zingiber monophyllum, a wild species of ginger is listed as Endangered.

DID YOU KNOW

Global figures for the 2012.1 IUCN Red List of Threatened Species:

TOTAL SPECIES ASSESSED = 63,837
(Total threatened species = 19,817)

Extinct = 801
Extinct in the Wild = 63
Critically Endangered = 3,947
Endangered = 5,766
Vulnerable = 10,104
Near Threatened = 4,467
Lower Risk/conservation dependent = 255 (this is an old category that is gradually being phased out of the Red List)
Data Deficient = 10,497
Least Concern = 27,937



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