An alien species is a species introduced deliberately or unintentionally outside its natural habitat, as opposed to local species. Any species that does not belong to a particular area or a specific ecosystem can be considered as alien species (includes seeds, ovum, spores, or other substances that facilitate the reproduction of the species). On the other hand, an invasive species refers to a species that cause or may cause damage to the economy and environment, or alien species that threaten the health of humans. Therefore, alien species may not necessarily become invasive species.
With the convenience of transportation and the liberalization of trade, various invasive species are spreading rapidly via diverse pathways and causing harm around the world. For instance, more than 1,000 invasive species have successfully established in the United States, and at least one highly dangerous species exists in almost every area, resulting in an annual loss of over US$10 billion. Apple snails were illegally imported to Taiwan from Argentina in 1979. However, these apple snails were discarded because of poor sales. Because of apple snails' high reproductive ability and its omnivorous characteristic, they have caused great damages to aquatic plants all over Taiwan and have resulted in a loss of NT$1.3 million. Also, pinewood nematode was first found in Shi Men Town, Taipei prefecture in 1985, and has spread from northern to southern Taiwan. As of now, its damage to forest areas is still prevalent throughout the country. Another threat is the American rope, a well-known "plant killer" found in the mountain areas of Hualien, Taitung, Chunghua, and Nantou. Its seeds are small in size (about 1 g per 1000 seeds), and are easily dispersed to distant areas through wind, insects, animals, or humans. American rope reproduces fast and has a strong rooting ability. Plants covered with American ropes are deprived of exposure to sunlight, and some even die from this impact. If the spread of American rope is not suppressed, it may lead to serious and harmful circumstances.
In order to prevent the negative impact of alien species on Taiwan's economy and environment, the Bureau of Animal and Plant Health Inspection and Quarantine (BAPHIQ), Council of Agriculture, Executive Yuan has established management mechanisms, organized numerous management projects, and promoted prevention and treatment plans. BAPHIQ convened a conference on biological management in 2003 to discuss the regulation and management mechanisms of invasive species in Taiwan as well as in other countries. It was intended to reach a consensus, through discussions and interactions, on how to effectively manage invasive species.
Hazardous alien species have caused severe agricultural losses and have considerably damaged the natural environment. Invasive species such as apple snails, pinewood nematode, and red imported fire ants have increased the cost of agricultural production as well as the prevention and treatment of invasive species. For instance, Polynesian rats were first discovered in May 1999. Besides harming crops such as rice, the ecosystem was also seriously affected and threatened. Another hazardous alien species is the cycad aulacaspis scale insect found in Taoyuan district in 1990. The cycad aulacaspis insect injures the whole cycad plant, including the frond, bulb, and root. It often draws juice from parts of the frond, eventually causing the frond to become brown and desiccated. The whole plant may then wither if seriously injured. The cycad aulacaspis scale insect has a high reproductive capacity, and is able to spread via wind, human mobility, or the movement of seedlings.
Damage by the golden mussel was first recorded in the upper reaches of Taipei Sindian River, causing serious blockage of raw water intake in Chintan dam. Golden mussels affected water-generated electricity, altered the ecological system of the lakes and rivers, simplified biological fauna, influenced the normal operation of plumbing systems, and affected the quality of water and human health. Yet, another invasive species is the water hyacinth, which was first introduced into Taiwan for its ornamental value during Japanese colonization. Today, it has caused blockage of irrigation canals, drainage canals, waterways, reservoirs, and power plants. It also reduced the efficient use of waterways, caused extinction of wild animals, altered the ecosystem, caused lack of oxygen in the water, and increased evaporation of water by 3.5 times. Water hyacinth also caused unnecessary waste of water resources, destruction of aquaculture breeding facilities, and proliferation of harmful insect habitats.
The many-lined sun skink was first found in Cheungching Lake in Kaohsiung and in Chungcheng Lake in Meinung. It may have caused the decline in garden skinks and grass lizards in the southern plain areas. Many-lined sun skink consumes local species because it has a large appetite and devours without selection. If the scope of invasion continues to spread, local lizards may possibly become extinct.
The National Sustainable Development Commission, Executive Yuan, is now implementing a policy on "enhancing management of invasive species" which aims to prevent alien species invasion in order to preserve the natural ecological environment. The COA convened the first meeting of the Committee on Promoting Biodiversity in February 2003, where it was agreed that an action plan will be implemented by BAPHIQ, assisted by agencies under the COA, namely the Endemic Species Research Institute, Agricultural Research Institutes, and Agricultural Research and Extension Stations. Due to the complexity of management and the involvement of numerous sectors, the assistance of the National Sustainable Development Commission has been tapped, while BAPHIQ established the Advisory Committee for Enhancing the Management of Invasive Species in March 2003. The work of the committee includes: establishing mechanisms to control alien species; building a prevention, quarantine, and monitoring system; constructing a risk assessment mechanism to evaluate whether alien species are invasive species; setting up a mechanism for assessing, managing and monitoring the introduction, release and escape of alien species; implementing prevention and control measures for invasive species; and constructing a detailed list of alien species.
Invasive species are divided into four main categories: animals; plants; aquatic animals and plants; and harmful organisms of animals and plants. The four categories are further divided into 11 groups of invasive species, and regulated by competent authorities in accordance with relevant laws. The managing authorities and related laws are presented in
Invasive species pose great threat to domestic ecosystem and economy. For their control and management, they have been classified into different levels according to possible scope of damage. After assessment, the following ten invasive species are currently selected for management: Polynesian rat, pinewood nematode, Psylla chinensis, cycad aulacaspis scale, red imported fire ant, apple snail, golden mussel, water hyacinth, American rope, and many-lined sun skink. The competent authorities are responsible for public education, monitoring, and control. As listed by BAPHIQ, the objectives in managing these ten invasive species are shown in
Table 2 and
To implement management of invasive species, the COA has invited experts and scholars; the Ministries of Interior, Defense, Finance, Education, Economic Affairs, Transportation and Communications; and the Department of Health, Environmental Protection Agency, National Science Council, Public Construction Commission, National Council on Physical Fitness and Sports, and Coast Guard Administration to convene cross sectoral meetings. The goal is to monitor and control the aforementioned invasive species, and to reach a consensus on how to cooperate in addressing this concern.
Most of the ten invasive species are being managed by the COA and its agencies. Among them, the Polynesian rat has infested Taiwan for five years, but through effective control, its expansion has been suppressed and it now only exists in Jian County, Hualien. Psylla chinensis mainly occurs in Taichung and Miaoli. Red imported fire ants occur in the prefectures of Taoyuan, Taipei, and Chiayi. To restrain dispersion, an important task for all the sectors is to manage responsible areas. For instance, the Ministry of the Interior is responsible for national parks, while the Ministry of Transportation and Communications is responsible for harbors and airports. Also, the Coast Guard Administration takes action against smuggling activities, while the Ministry of Education takes responsibility for education and compilation of related educational materials.
The World Conservation Union (IUCN) has compiled a directory of top 100 dangerous invasive species, as well as invasive species from neighboring countries. This directory is used as reference to construct a list of possible dangerous species to effectively prevent dangerous invasive alien species from entering Taiwan. Cooperation among different sectors is required in order to successfully prevent such invasion.
Table 4 shows the important invasive species found in Taiwan and their impact in the past 30 years.
To prevent the invasion of foreign animal or plant diseases and pests and ensure the security of agricultural production and health of the people, BAPHIQ has been implementing the following programs:
Risk analysis for diseases and pests. Since the level of damage differs by disease and pests, scientific risk assessment will be carried out to determine the extent of risks in order to take appropriate sanitary and phytosanitary measures.
Inspection and quarantine of animal and plant importation. To effectively prevent dangerous foreign diseases and pests from being introduced into Taiwan through imported agricultural products, the BAPHIQ has been enforcing inspections and quarantine at seaports and airports. After joining the World Trade Organization (WTO), the importation of agricultural products have increased greatly, resulting in increased risk of invasion by diseases and pests. Statistics showed that in 2002, there were 68,419 lots of imported plants and plant products inspected and 96,037 lots of imported animals and animal products inspected. Despite the great varieties and quantities of these products, the Kaohsiung branch of BAPHIQ has detected codlin moth twice in apples imported from the United States in November 2002, and thus halted the importation of American apples to effectively block the pest invasion. Moreover, due to the thriving tourism around the world, the quantity and variety of plant and animal entering Taiwan with tourists have increased continuously, thus arousing great alert to quarantine service in preventing harmful organisms from introduction. Prohibition of bringing fresh fruits by tourists was enforced on October 1, 1998 so as to reduce entry of foreign diseases and pests.
As for exportation, the approach is not only to help expand international market for agricultural products and ensure the smoothness of exportation, but also to prevent the export of diseases and pests from Taiwan.
Establishment of canine team for quarantine and inspection. In view of the fact that passengers are a path to introduction of foreign diseases and pests, the BAPHIQ has established canine forces to strengthen inspection of plants and animals brought by tourists at the airport. Four canine teams have been in service at the Chiang Kai-Shek International Airport and the Kaohsiung Airport since October 2002, and have detected quite a lot of agricultural products in baggages. The rate of successful inspection is 90 percent.
On-site inspection in exporting countries. Pre-clearance is conducted annually by BAPHIQ by sending quarantine officials overseas to carry out on-site inspection and observation of disease and pest control practices, quarantine treatment and facilities, and quarantine service of exporting countries. Only those agricultural products that are in compliance with Taiwan's regulations are allowed to enter the island.
1. Prevention of Foreign Animal Infectious Diseases from Invasion
Monitoring of foreign infectious diseases. Rinderpest, bovine spongiform encephalopathy (mad cow disease), highly pathogenic avian influenza, and rabies are all infectious animal diseases and zoonosis. To prevent such diseases from entering Taiwan, BAPHIQ not only prohibited animal and animal product importation from infected areas, but also implemented disease monitoring in cooperation with other relevant agencies to ensure prompt action upon early detection. Results of the monitoring show that Taiwan remains free from these infectious diseases.
Drills for emergency eradication of infectious animal diseases. Drills have been held over the years to alert people of animal epidemics that have potentials to invade, such as rabies, cattle plague, Nipa virus, and African swine fever. The practices help raise public awareness about the diseases and allow animal health inspection officials at all government levels to familiarize themselves with the procedures and practices to enable them to control the epidemics on the spot once found.
2. Strengthening Animal Diseases Notification
BAPHIQ utilizes a computer network for animal disease notification to consolidate information from all prefectures and cities. The network allows the animal health inspection and quarantine agencies to get detailed information of the epidemics. It also facilitates analysis of epidemiology of diseases and the follow-up control.
3. Eradication Program for Hog Cholera and Foot-and-Mouth Disease (FMD)
Since the outbreak of the foot-and-mouth disease (FMD) in 1997, the government has implemented an eradication program for swine fever (hog cholera) and FMD. In its current implementation phase, the policy of thorough vaccination is enforced. Through the collaborative efforts of animal health inspection agencies at all levels and the cooperation of farmers, no outbreak has been detected for over two years since the last FMD outbreak in February 2000. Taiwan thus filed an application to the World Organization for Animal Health (OIE) and was recognized as an "FMD-free country with vaccination" on May 22, 2003. Various measures concerning the eradication of FMD are practiced continuously in the hope of moving on to discontinuing vaccination and to eventually achieve the status of "FMD-free country."
1. Strengthening Plant Diseases and Pests Notification
BAPHIQ has established a computerized monitoring and pest report system to achieve thorough monitoring, immediate notification, and precise diagnosis toward issuance of early warnings and to take preventive or control measures immediately. For the detection of foreign diseases and pests, BAPHIQ has founded a detection network with 1,014 spots in high-risk areas such as major agricultural production areas, collection and distribution center of import agricultural products, and ports. The network aims at detecting significant alien pests such as Mediterranean fruit fly, codlin moth, Western flower thrip, bulb mite, and other fruit flies. None of the pests have been found in Taiwan yet.
2. Enforcement of Emergency and Collaborative Control of Plant Diseases and Pests
To stop invasive diseases and pests from spreading, BAPHIQ keeps track of the country's pest situation through its monitoring system and coordinates with relevant plant agencies to undertake emergency control and collaborative control protection. For instance, when pear decline was found in 1994, BAPHIQ immediately established a control project and adopted urgent control measures, including the investigation and monitoring of the situation, development of diagnostic technology, and removal of infected plants to stop the spread of the disease.
3. Emergency Control Drill
In order to adopt emergency control measures upon detection of foreign pests, BAPHIQ formulates action plans and holds emergency control or eradication drills. In doing so, BAPHIQ familiarizes relevant plant protection agencies and farmers with the standard procedures for control and eradication.
Taiwan is a member of the World Trade Organization, the World Organization for Animal Health (OIE), and the Asia and Pacific Economic Cooperation, and actively participates in meetings held by these international organizations related to sanitary and phytosanitary issues.
As a member of APEC, Taiwan hopes to strengthen its regional collaboration in monitoring invasive alien species. Hence, BAPHIQ organized a symposium on "Detection, Monitoring and Management of Invasive Plant Pests" in September 2002. Eighteen economies with nearly 60 participants including officials of quarantine, scholars, and experts were invited to strengthen communication and cooperation in the detection, monitoring and control of invasive plants and pests among the economies. The purpose was to increase the capacity to prevent invasions of plant pests and to establish an international support system so as to forestall the occurrence, spread, and damage of the serious plant pest situation within the Asia-Pacific region.
To make the public aware of the serious impact of plant and animal diseases and pests and the importance of their control to the public, BAPHIQ organizes various lectures, exhibitions, summer camps for children, and training for school teachers. Promotions through media, magazine, and other means such as single sheet flyers, pamphlets, etc. are also adopted. BAPHIQ also collaborates with other government agencies including the customs, the Tourism Bureau, and local governments to communicate the issue with the industry and the people. The goal is to alert people of the importance of disease and pest prevention and to enforce necessary inspection and quarantine policies of the government in the hope of preventing the invasion and spread of diseases and pests.
Red imported fire ants originate from the Parana River area (including Brazil and Argentina) and invaded the south of the United States in the early 1930s; at present, fire ants have been threatening 14 states. Red imported ants also invaded New Zealand and Australia in 2001. In 2003, potential cases of fire ant invasion were reported in Taoyuan and Chiayi in Taiwan. Later, they were confirmed by the Department of Entomology of the National Taiwan University (NTU).
So far, red imported fire ants have been detected in Taoyuan, Chiayi, and Taipei through constant monitoring, and some cases were found in Taipei city and in Miaoli and Yilan prefectures.
In April 2004, COA held a workshop for the urgent prevention of invading red imported ants. BAPHIQ has employed, in collaboration with other government agencies, chemical control methods to control the invasion.
A seminar for red imported fire ant control was held on October 5, 2004 attended by delegates from the Environment Protection Administration (EPA), the Department of Health, the Ministry of Education, the Ministry of National Defense, the Ministry of Interior, the Ministry of Economic Affairs, and the Ministry of Transportation and Communication to learn about the standard procedure to control red imported fire ants as part of the eradication project and to conduct follow-up monitoring. The eradication project includes gathering and study of information, establishment of a communication mechanism, purchase of pesticides and equipment, monitoring and control, and medical training.
The National Red Imported Fire Ant Control Centre was founded on November 1, 2004. The Centre has engaged experts and scholars in relevant fields and officials of the BAPHIQ to fulfill the responsibility of offering professional consultation, monitoring, and evaluation of the control. Local task forces were also assembled to implement the control procedure in two phases. The first phase is to efficiently control the density of the red imported fire ants by the end of 2004. The second phase is to eradicate the red fire ants within three years (2005-2007) or to reduce its density to the utmost to forestall its damage.
Due to increased international agricultural trading, the risk of plant pest invasion has been growing through the years. Take the Mediterranean fruit fly for instance: Taiwan's agriculture will be seriously threatened if the pest successfully invades the island. Moreover, agricultural exportation will be blocked for failing to meet the quarantine requirements of other countries due to the occurrence of the pest. The invasion will not only have serious impact on the development of agriculture but also on the economy itself. Realizing the danger of invasive alien species, the government and the people must work together against the invasion of these foreign diseases and pests. Upon the detection of new invasive species, urgent control measures must be taken immediately to forestall their spread. The risks of alien species invasion should be seriously considered. Relevant research should be promoted. It is also necessary to fortify cooperation among relevant agencies and nongovernment groups at all levels and effectively respond to the incessant threats of invasive diseases and pests that the country faces after joining the WTO.
Table 1 Competent Authorities and Laws for the Management of Invasive Species
Table 2 Management Strategy for Invasive Species
Table 3 Management Strategy for Invasive Species
Table 4 Important Invasive Species in Taiwan and Their Impact in the past 30 Years
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