Invasive Snail, Other Species Threaten China's Eco-Security

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Over the past three months, the Amazonian Snail, also known as the golden apple snail, has wreaked havoc on public health and agricultural land in China. Since June, the city of Beijing has reported 131 cases of people infected with Angiostrongylus cantonensis, a lungworm parasite carried by the mollusk, which is native to South America. More than 170,000 hectares of rice paddies in southern China’s Guangxi province have also been affected by the snail, costing the local government 530,000 RMB (US $66,000) in eradication fees.

The Amazonian snail (Pomacea canaliculata) was first introduced into Taiwan as a high protein food in 1979, then introduced into Guangdong in 1981. It is generally considered safe and nutritious to eat, and is served as a gourmet offering in many Chinese restaurants. If eaten raw or half-cooked, however, the snail can cause Angiostrongylus infections in humans, with symptoms ranging from headaches and low-level fever to nausea and possible meningitis. Listed as one of the world’s 100 most devastating invasive “alien” species by the World Conservation Union (IUCN), the mollusk also damages agricultural land: with its high rate of reproduction and ravenous appetite, it can rapidly destroy newly transplanted or directly seeded rice.

According to Zhao Liangping, director of forest pest and disease prevention at China’s Ministry of Forestry, invasive pests cause direct economic losses of 56 billion RMB (US $7 billion) every year, threatening the nation’s environmental security. Xinhua News Agency cited a nationwide survey of forest pests showing that China’s exotic species imports have jumped considerably in recent years. While only 10 invasive alien pests were reported in 1980, the figure has since more than doubled to 26. Of these, some 81 percent were detected in imported host plants and 13 percent were transported in timber and wood-based packing material.

China is one of the world’s most biologically diverse countries. With more than 30,000 different varieties of plants, it boasts the third largest plant diversity on Earth, after Brazil and Columbia. But China’s diverse habitats and environmental conditions also make it particularly vulnerable to the impacts of invasive species.

Most industrial countries, including nearby Pacific nations like Australia, Japan, and New Zealand, have enacted special legislation to prevent invasive species. The United States established its invasive species law in 1996, and Canada has issued “Tactics on Invasive Alien Species” to protect local ecosystems. In China, however, rules on importing exotic species are found only in the nation’s Law of Entry and Exit Animal and Plant Quarantine, indicating the lack of a sound and effective mechanism for keeping devastating foreign invaders out.