Current Status of Invasive Alien Species Management

I. Introduction

According to the guidelines of the Convention on Biological Diversity (CBD), an alien species is defined as a species, subspecies, or lower taxon introduced outside its past or present natural distribution range, including any part capable of survival and subsequent reproduction, such as gametes, seeds, eggs, or propagules. An invasive alien species (IAS) is defined as “a species whose introduction and/or spread threatens biodiversity.” The International Union for Conservation of Nature (IUCN) further defines invasive alien species as alien species that establish themselves in natural or semi-natural ecosystems or habitats, cause ecological changes, and pose threats to local biodiversity. The pathways for the introduction of alien species can be divided into unintentional and intentional introductions. Unintentional introductions are complex and include species arriving via transportation vehicles, goods, or legally imported plants and animals, as well as pathogens and insects associated with agricultural and livestock products, making them difficult to prevent. Intentional introductions are usually linked to human interests and include species legally introduced or smuggled for purposes such as breeding, aquaculture, biological control, scientific research, recreation, and ornamental use.

In recent years, with increasingly convenient transportation and expanding trade, many alien species have rapidly spread worldwide through various pathways, causing ecological harm. The introduction of alien species occurs through both unintentional and intentional pathways. Unintentional introductions are often complex, involving species transported accidentally on vehicles, goods, or legally imported plants and animals, as well as pathogens and insects carried with agricultural or livestock products, making them difficult to prevent. Intentional introductions, on the other hand, are generally driven by human interests and include species brought in legally or smuggled for purposes such as breeding, aquaculture, biological control, scientific research, recreation, or ornamental use.

II. Management Mechanism

To strengthen environmental protection, safeguard social equity and justice, promote economic development, and build a green Silicon Island, the Executive Yuan established the National Council for Sustainable Development in August 1997. In May 2000, the Council formulated “Agenda 21 - Strategic Guidelines for ROC's Sustainable Development” as the foundation for Taiwan’s sustainable development policies. Starting in June 2002, with reference to global trends and action plans from world summits on sustainable development, Taiwan developed its own sustainable development action framework. This included tasks, principles, work items, specific measures, lead and co-responsible agencies, and implementation timelines. The framework was drafted through broad consultations with experts, scholars, and public forums and was finalized as the “Sustainable Development Action Plan,” guiding Taiwan’s efforts in the early 21st century.

To prevent the invasion of alien species and protect native ecosystems, the Council designated “Strengthening Invasive Species Management” as a priority under the “Biodiversity Working Group” in the Action Plan. In 2001, the National Biodiversity Promotion Plan included “Alien Species Management” as a key initiative. This focus was revised in 2004 to “Strengthening Invasive Species Management” and further updated in 2007 to “Controlling Invasive Species Threats,” which includes the following work items:

1. Establish a management mechanism for the import and export of alien species, including species import and export controls and quarantine measures.
2. Develop a risk assessment and ecological impact evaluation system for alien species introductions, using the results to formulate monitoring and control strategies.
3. Establish monitoring, identification, and early warning systems for alien species, including follow-up management of imported species (such as pet management).
4. Strengthen enforcement against the smuggling of alien (invasive) species.
5. Implement biological control measures for invasive species:
(1) Develop emergency eradication plans for new invasive species and conduct regular joint exercises with local governments.
(2) Establish long-term control plans for invasive species to minimize economic losses and ecological impacts.
6. Establish lists of alien and invasive species:
(1) Compile a national list of alien and invasive species, analyze their ecological and economic impacts, and propose management strategies.
(2) Establish a list of high-risk invasive species of international concern, analyze pathways of introduction, and propose preventive measures.

To prevent invasive species from harming Taiwan’s ecology and economy, the Ministry of Agriculture (formerly the Council of Agriculture) has integrated its subordinate agencies to establish an “Invasive Species Management Mechanism” based on assigned responsibilities. Key tasks include developing regulations, disease prevention, quarantine, and monitoring systems for alien species; conducting risk assessments to identify invasive species; and evaluating, managing, and monitoring the impacts of alien species introductions, releases, and escapes. The Ministry also actively implements control measures to protect native biodiversity and prevent zoonotic diseases, while maintaining species lists to safeguard Taiwan’s ecological integrity and agricultural production security.

Since the government reorganization in 2023, responsibility for coordinating invasive species management has been transferred from the Forestry and Nature Conservation Agency (formerly the Forestry Bureau) to the Department of Resources Sustainability, Ministry of Agriculture.

III. Implementation Strategies

To prevent the continued invasion of alien species, the Forestry and Nature Conservation Agency has consolidated legal foundations and clarified the division of responsibilities to implement effective control measures and promote prevention and management actions. The strategies are as follows:

1. Border Control
(1) Strengthening border restrictions: To block the entry of invasive species, a second list of prohibited imports covering 53 categories and 8,478 species was reviewed and submitted to the International Trade Administration. It was announced on May 19, 2022, under the Foreign Trade Act as an amendment to the List of Commodities Subject to Import Restriction and took effect on June 1, 2022. Unless specifically approved, these species may no longer be imported, thus preventing invasive species at the source. Rolling reviews will continue, and additional species identified as high risk will be added dynamically to the third list of prohibited imports.
(2) Strengthening species import controls: The principle of "prohibited in general, exceptions permitted" applies to animal imports. For species with no previous import records, each case is reviewed individually. If applications raise concerns about risks to native ecosystems, animal welfare, or disease, joint reviews are conducted with relevant agencies and experts. If any party objects to the import, approval is denied. Previously imported species are re-examined for potential invasion risks, public health and zoonotic concerns, animal welfare, or disease transmission among wildlife, and may be added to the third list of prohibited imports.

2. Domestic Management
(1) Eradication of invasive species:
a. From 2019 through the end of 2022, efforts removed 4,431 hectares of mile-a-minute weed, purchased 1,274 metric tons of its biomass, and controlled 1,288 hectares of parthenium weed, 710 hectares of river tamarind, and 52 hectares of giant sensitive plant. For 2023 to 2024, removal of 1,670 hectares of river tamarind is planned on the Hengchun Peninsula, accompanied by native tree planting for habitat restoration. Biomass from removals will be developed for bioenergy conversion.
b. From 2019 to 2022, 98,291 green iguanas, 18,076 adult sacred ibises, and 3,896 cane toads were removed as part of eradication efforts. Additionally, under Article 31 of the Act on Wildlife Conservation, green iguanas and cane toads were designated as species requiring registration for continued keeping on August 20, 2020, and April 7, 2022, respectively. Breeding without approval is prohibited and subject to fines ranging from NT$10,000 to NT$50,000, with possible confiscation of the animals.
c. Guidelines for the humane removal of terrestrial invasive animals are continuously updated to ensure eradication efforts avoid improper capture or mistreatment. These guidelines balance ecological protection with animal welfare and aim to prevent abuse.

(2) Preventing improper animal release and promoting ecological rehabilitation: In collaboration with the Ministry of the Interior, outreach efforts to religious groups emphasize ecological conservation concepts. The goal is to encourage their participation in the “ecological release of rehabilitated wildlife,” shifting the traditional practice of religious release toward conservation-based life protection.

(3) Enhancing public education and outreach: Public campaigns through various media strengthen awareness of ecological conservation and respect for wildlife. A cross-agency prevention and control platform has been established to integrate private-sector resources and reduce government expenditures.

3. Regulatory Enhancement
Drawing on the regulatory frameworks of countries such as the United States and China, Taiwan likewise does not have a dedicated invasive species act; instead, management is dispersed across existing laws. According to the “Guidelines for Drafting Laws and Regulations by Central Administrative Agencies,” a new law should only be proposed when no current laws can apply or be amended to apply. Furthermore, Article 5, Paragraph 3 of the Basic Code Governing Central Administrative Agencies Organizations stipulates that the establishment of agencies or staffing matters may not be regulated by functional laws or other regulations. Accordingly, the enactment of a dedicated invasive species law would have to be carried out within the current organizational framework and would risk creating further jurisdictional overlap. The chosen approach is therefore to strengthen the Ministry of Agriculture’s existing sectoral regulations for invasive species management rather than drafting a new law.

IV. Future Outlook

In recent years, invasive alien species have become a highly visible issue, frequently reported for their ecological impacts. Public awareness and concern among conservation groups have grown substantially. The Ministry of Agriculture has increased funding to support research, surveys, and control and removal initiatives. However, given the large number of alien species and their numerous pathways into Taiwan, effective prevention and management demand coordinated cooperation across a wide range of government agencies and stakeholders. These include branches of the legislature and judiciary, customs, agriculture, forestry, fisheries, animal husbandry, marine affairs, environmental protection, education and outreach, shipping, civil aviation, transportation, national defense, and international trade, as well as institutions such as zoos, botanical gardens, pet breeders, importers, and universities. The success of invasive species management in Taiwan hinges on effective collaboration and clear division of responsibilities among these diverse parties

The Forestry and Nature Conservation Agency will continue to collaborate closely with agencies under the Ministry of Agriculture to address invasive alien species in line with their assigned responsibilities. Key efforts include strengthening import control, quarantine, and monitoring mechanisms, conducting risk and impact assessments, and implementing effective management and monitoring systems. The Agency will also maintain continuous communication and coordination with other ministries and establish international information-sharing networks to align with global management practices and prevent the cross-border spread of invasive species. Further, the Agency will continue to subsidize and oversee local governments in carrying out invasive species removal operations with the goal of protecting Taiwan’s ecosystems and minimizing the economic and social impacts caused by invasive alien species.