Previous Page Table of Contents Next Page


Section 1
Global overview of the management of invasive alien species

Information digest of section 1


Section 1 provides a detailed overview of the various agreements and programmes governing management of invasive alien species at the international level. It discusses the recent cooperative work by international bodies to prevent the spread of invasive alien organisms and reduce their impacts. It also illustrates the variety of negative impacts that can occur when alien species become invasive in an area.

CBD definitions

alien species: a species, subspecies or lower taxon, introduced outside its natural past or present distribution; includes any part, gametes, seeds, eggs, or propagules of such species that might survive and subsequently reproduce

invasive alien species: an alien species whose introduction and/or spread threaten biological diversity

IPPC definitions

[plant] pest: any species, strain or biotype of plant, animal or pathogenic agent injurious to plants or plant products

quarantine pest: a pest of potential economic importance to the area endangered thereby and not yet present there, or present but not widely distributed and being officially controlled

Instruments pertaining to the management of invasive alien species

The foremost international convention obliging its contracting parties to take action on invasive alien species is the Convention on Biological Diversity, which was adopted in 1992. The objectives of the convention are the conservation and sustainable use of biological diversity and the fair and equitable sharing of benefits arising out of the utilization of genetic resources. Article 8(h) of the CBD requires contracting parties to prevent the introduction of, control or eradicate those alien species which threaten ecosystems, habitats or species.

The International Plant Protection Convention, which came into force in 1952, also contains provisions applicable to invasive alien species when the species concerned are pests of plants or plant products. The IPPC aims to prevent the spread and introduction of pests of plants and plant products, and to promote appropriate measures for their control. The IPPC definition of a quarantine pest covers much, but not all, of what is considered as an invasive alien species under the CBD. Both definitions refer to any organism that is injurious to plants and that has an environmental impact. Although sometimes perceived as limited to the protection of agricultural and forestry plants, the IPPC covers all plants, including those found in natural and semi-natural habitats.

Many other international and regional instruments are relevant to managing the spread and negative effects of invasive alien species. Some 50 instruments or guidelines deal with particular aspects of the management of invasive alien species. Examples are listed below.

Major international instruments relating to invasive alien species:

Instruments dealing with invasive alien species in the context of particular species groups include:

Examples of instruments and programmes dealing with invasive alien species in the context of particular ecosystems are:

Instruments dealing with invasive alien species in the context of particular pathways for their introduction include:

Given the large number of such instruments, it is important for countries to be guided in how to develop national strategies on invasive alien species and understand how to put them into practice without running into conflict between one instrument and another. Measures to prevent the introduction of invasive alien species may, by their nature, be very trade restrictive. Therefore, members of the World Trade Organization must ensure also that any measures relating to invasive alien species are in accord with their obligations under international trade rules.

Recent developments under the CBD framework

In 2002, the CBD formalized a set of guiding principles on alien species that threaten ecosystems, habitats or species (refer footnote on page 7). These guiding principles comprise six general principles, three dealing with prevention, two with introduction of species and four with mitigation of impacts. The 15 subject areas are:

Many of the recommendations within these guiding principles correspond with provisions of the IPPC and its international standards for phytosanitary measures.

Other aspects of the CBD’s programme of work on invasive alien species include a toolkit of prevention and management practices, a guide to designing legal and institutional frameworks, an analysis of gaps and inconsistencies in the international regulatory framework and an analysis of the ecological and socio-economic impact on island ecosystems and on inland water ecosystems. All of these relate to invasive alien species.

Recent developments under the IPPC framework

Since 1999, the governing body of the IPPC has devoted considerable effort to clarifying the role of the convention in relation to invasive alien species. In 2001, it formally determined that implementation of the IPPC is directly relevant to implementation of Article 8(h) of the CBD. It also agreed that many provisions and standards of the IPPC are directly relevant to, or overlap with, the (then interim) guiding principles of the CBD on invasive alien species. In particular, ISPM 11 [2001]: Pest risk analysis for quarantine pests was to be developed to address in detail the environmental risks of plant pests. The revised standard, ISPM 11 rev. 1: Pest risk analysis for quarantine pests including analysis of environmental risks, was adopted in 2003 and further revised and supplemented in 2004.

Also in 2003, ISPM 5: Glossary of phytosanitary terms, was supplemented with Guidelines on the understanding of potential economic importance and related terms including reference to environmental considerations. This clarifies that the IPPC can account for environmental concerns in economic terms using monetary or non-monetary values; market impacts are not the sole indicator of pest consequence. Thus the scope of the IPPC covers the protection not only of cultivated plants but also of uncultivated/unmanaged plants, wild flora, habitats and ecosystems.

Collaborative international initiatives

Since 2001, the CBD and the IPPC have worked together in their efforts to help countries deal with the threat posed by invasive alien species. The aim is to avoid duplication of activities, contradictory approaches and a confusion of competences. A Memorandum of Cooperation has been established to formalize the arrangement between the two secretariats.

The CBD has recommended that its contracting parties consider ratifying the IPPC. It has invited collaboration in development of standards (such as those of the IPPC) when they could incorporate elements relating to threats to biodiversity posed by alien species. There has been close collaboration between both conventions in the 2003 revision of ISPM 11. The CBD also works in partnership with the IPPC in information exchange endeavours such as the International Phytosanitary Portal and International Portal on Food Safety, Animal and Plant Health.

Range of adverse impacts

Cooperative international effort to foster the management of invasive alien species is particularly important because the problem is global. No single country can successfully control the spread and impacts of alien species when trade and travel promote the dispersal of such organisms and when their effects in a new territory may be unforeseen. The extent and range of adverse impacts makes cooperative action essential.

Although many alien species offer great benefits to a country (e.g. in agriculture, forestry, aquaculture), those species which become invasive can have devastating impacts. The negative impacts may be environmental through loss of biodiversity, economic through a loss of production by affected species or the cost of control measures, health-related (e.g. when the invasive organism is a host or vector for disease) or political through effects on international trade, food security, water supply, regional stability, poverty, migration etc.

Invasive alien plants have a range of impacts on native biodiversity and ecosystems. They may compete with native taxa of flora, hybridize with genetically close species, alter the physical and chemical characteristics of soil, modify natural and semi-natural habitats, and propagate pests and diseases. The ecosystems most vulnerable to invasion are geographically and evolutionarily isolated ecosystems (islands, mountain ranges, lakes etc.) whose flora and fauna have evolved over millions of years.

Using the IPPC framework

National phytosanitary authorities have a long experience in the assessment and management of biological risks related to the introduction of organisms. They possess the knowledge of how to deal with risks posed by plant pests. This existing infrastructure and know-how could be utilized by environmental authorities in their efforts to implement the guiding principles of the CBD.

The IPPC has been in effect for more than 50 years; over the past decade it has been developing a suite of international standards for the use of national plant protection organizations. IPPC-related activities are administered in many countries by agricultural authorities and CBD matters by environmental authorities. Communication between these authorities in relation to invasive alien species is important.

Section 1 suggests that, with its increased focus on environmental risks of plant pests, the IPPC provides a suitable framework to manage the introduction, control or eradication of invasive alien species that are plant pests. The infrastructure of national plant protection organizations is in place; the body of experience is well developed; relevant, user-friendly, international standards are in existence and more are being developed or revised; the necessary information exchange systems are established.

Gaps and constraints in mitigating the effects of invasive alien species

In addition to a lack of resources, common constraints at the national level include:

The impacts of invasive alien species may extend to a group of neighbouring countries. Constraints on effective action at the regional level include lack of awareness, and poor coordination and cooperation between sectors and between neighbouring countries. Another problem arises with changes to regional free trade arrangements without consideration of the risks associated with liberalizing border controls and of management needs for invasive alien species already present within the free trade area.

Many pathways and vectors are still not adequately covered by international rules, guidance or codes of best practice. For example, seeds, food and other commodities moving in the course of development assistance, humanitarian or military operations fall outside the regulatory framework for conventional trade pathways. In 2004, the Conference of the Parties to the CBD identified a number of cases in which invasive alien species are not covered by the international regulatory framework.

The approach to invasive alien species is usually a defensive one. Existing frameworks do little to support “prevention through avoidance”. There are few deterrents to the continued use of environmentally harmful species in some sectors and few incentives to promote the use of native species as an alternative to introduced species. There are few preventive rules to restrict exports of high-risk invasive plants or animals to countries where they are likely to be problematic. There are virtually no international early warning systems for invasive alien species as they affect wild species and natural or semi-natural systems.

Plants and animals that are invasive in their own right are covered under IPPC or OIE only if they qualify as plant pests or animal diseases. There is a lack of international standards for “environmental pests”. Recent supplements to ISPMs do not extend the IPPC definition of “plant pest”. The extension of some ISPMs to address environmental risks and costs will open up a new area for many plant health regulators.

More advanced tools are needed to deal with risk assessment and environmental assessment. Outside mainstream agriculture and forestry sectors information is lacking and impacts, except for particularly invasive species, are largely unknown. Existing tools do not usually cover ways to deal with species already present in a country and to determine factors of vulnerability for receiving environments.

Constraints on funding and gaps in institutional coordination are also areas that need addressing.

Recommended steps

Section 1 suggests that common goals for all levels (international, regional, national) should include making best use of existing regulatory frameworks, strengthening cooperation between key organizations and targeting existing tools and resources more effectively to encompass biodiversity-related impacts. Recommendations for action at the national level include development of policy and regulatory frameworks and the engagement of relevant community groups and entities:

This digest consists of information extracted from section 1, together with some background material and explanatory comment. For the full detail, argument, examples and supporting references, please refer to the following chapters 1-3.


Previous Page Top of Page Next Page