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Methodology for assessing the legal regime for phytosanitary control of invasive alien species

George Agyemang Sarpong

Senior Lecturer, Faculty of Law, University of Ghana, P.O. Box 70, Legon, Ghana; e-mail:


This paper, drawing on the Ghanaian experience, provides a methodology that could be used by other countries seeking to improve their ability to control invasive alien species. National legislation and institutions need to be assessed and the requisite changes identified. The process includes an examination of appropriate global and regional instruments dealing with biological diversity, an assessment of existing national legislation in relation to these instruments and the adoption of any new legislation necessary to cover shortcomings. The methodology describes the form of legislation to be implemented and the resources necessary for implementation.


The problem of invasive alien species is one with international dimensions and consequences, as demonstrated in the preceding chapters; accordingly, the international community has formulated treaties and standards to address the subject. These include, in particular, the Convention on Biological Diversity and its guiding principles on invasive alien species (refer footnote on page 7) and the International Plant Protection Convention and its standards for phytosanitary measures. But how are these treaties and standards to be implemented at the domestic levels?

This paper proffers a methodology that could be used by countries in identifying and assessing their institutional and legislative frameworks for the control of invasive alien species. It entails an examination of relevant global and regional instruments on biological diversity, including invasive alien species, an assessment of existing legislation in the country in the light of these instruments, the adoption of the required legislation to fill the gaps, and the nature or form of legislation to be implemented. The work is the outcome of a study conducted for the IPPC Secretariat on the legal regime for phytosanitary control of invasive alien species in Ghana. The methodology may thus not be applicable in all jurisdictions but it is certainly worth considering, especially for developing states that adhere to the common law tradition.

Outline of the methodology

The various elements/stages of the methodology may be summarized as follows:

Nature and sources of introduction of invasive alien species

Identification of the nature and sources of introduction of invasive alien species is of paramount importance. There is a need to assess the nature and/or sources of the IAS problem in the country so as to identify the priority areas for action. In this regard, it may be recalled that the causes and/or sources of introduction of invasive alien species could be either intentional or unintentional and through various pathways, including air, land and sea (travel, trade, tourism etc). The provision of accurate information on plant health status in a country is of crucial importance because, inter alia, it provides an informed basis for the provision of preventive or eradication measures under the legislation.

Applicable global and regional instruments

The methodology involves identification of the applicable global and regional instruments governing invasive alien species. The major global instruments that address the subject include:

Further information on these instruments is available in preceding chapters (e.g. chapter 3).

There are, in addition, regional instruments of relevance to the subject. Some examples include:

There are also soft law instruments that address the subject. These include:

Although legally non-binding, these soft law instruments are nevertheless of importance as they serve as guides or the basis for action or conduct on the part of states in the implementation of measures for the control of invasive alien species.

It is the provisions of these instruments that constitute the norms, benchmarks or standards against which national standards may be enacted and/or measured. In this regard, the CBD and its guiding principles and the IPPC and the ISPMS are of paramount importance.

Ratification status of applicable instruments

The next step in the methodology is determination of the ratification status of the applicable instruments. If the instruments have not been ratified, one must determine what are the necessary steps for ratification.

In common law jurisdictions, treaties entered into by states are usually not directly enforceable in the courts unless enacted as legislation at the domestic level. This contrasts with the situation in other jurisdictions such as the United States where treaties form part of the law. The treaty-making or ratification power is governed by the constitutional order or arrangement.

In Ghana, for example, the treaty-making power is the prerogative of the president under and by virtue of Article 75(1) of the 1992 Constitution. However, a treaty executed by the president shall be subject to ratification by parliament. Ratification is usually on the basis of a resolution adopted by parliament after a review or examination of the relevant treaty. Once ratified, an instrument of ratification must be deposited with the designated depository under the convention.

A treaty ratified by a state is binding on that state under the principle of pacta sunt servanda (“pacts must be respected”). Accordingly, the state would be enjoined, where the treaty is not directly applicable at the domestic level, to enact appropriate legislation to give force and effect to the provisions of the treaty. This is usually the case with common law jurisdictions.

Existing relevant legislation and institutions

The methodology now turns to identification of the existing relevant legislation and institutions on the subject. Throughout the legal systems in all jurisdictions, there are sources of law from which to ascertain the relevant legislation on a subject. In the common law tradition these include the constitution, parliamentary enactments, subsidiary legislation and the common law.

The constitution is the fundamental law of the land and all laws or enactments inconsistent with the constitution are null and void. For the majority of states, the constitution, is captured in a written document or documents, as in Ghana or India; in rare instances, it may be unwritten, as in the United Kingdom. The constitution also usually provides for the sources of law in a particular jurisdiction. Article 11 of the 1992 Constitution of Ghana, for example, provides as sources of law, the following:

In many jurisdictions, legislative enactments provide the main body of rules or law on many subjects including the environment. There could be a single legislature, as is the case with unitary states, or a two-tier system of legislation with federal laws and state laws, as in federal states.

Subsidiary legislation in the form of regulations is most often employed as a means of providing detailed implementation of the law in environmental legislation. Regulations are of extreme importance in the area of environmental law because they provide a flexible means for review or update of the law without recourse to the amendment of the parent enactment. The amendment process is comparatively cumbersome, time-consuming and therefore ineffective in coping with the desired changes in legislation demanded by changing times or circumstances, including the emergence of new technology or scientific data.

There are also codes of practices, directives or standards. These are not legally binding per se, but serve as guides to actors or operatives in a given sector in the performance of their functions.

The next step is an in-depth examination of each of the various sources of law to ascertain whether or not it addresses the subject of invasive alien species. For example, does the constitution make express reference to the environment, biodiversity, agriculture or other subjects that are likely to impinge on or address the subject? If the constitution does not expressly address the subject, could it be interpreted to apply to the control of invasive alien species? For example, even though the Ghanaian constitution does not expressly refer to biodiversity or invasive alien species, Article 36(9), which enjoins the state to protect the environment, could provide a basis for action on the subject of control of invasive alien species.

The examination of legislation could be an arduous task. In many jurisdictions, there may be hundreds or even thousands of pieces of legislation scattered throughout the statute books. Several jurisdictions publish a useful guide as an “Index to statutes” or “Index to subsidiary legislation”. In some jurisdictions, the legislation is captured in electronic form, such as on CD-ROM, which facilitates research. In the absence of a specific enactment on invasive alien species, the legislation in each relevant sector (e.g. forestry, game and wildlife, wetlands, marine environment, plant protection) could be examined in turn to ascertain whether or not any provisions address or impact on the control of invasive alien species. For example, in the forestry sector: do any provisions on existing forestry legislation specifically address invasive alien species? If so, the relevant provisions and the prescribed methods/measures provided for under the legislation would be noted.

Institutions with responsibility for the control of invasive alien species (or whose activities impinge on the subject) could include ministries or departments of state for agriculture, health, environment, transport, justice, interior and trade. Other relevant agencies or departments include the environmental protection agency, customs and immigration. The large number of relevant institutions in the field of control of invasive alien species is such as to lead to conflicts, overlaps and gaps in the regime. This may require the strengthening of the lead agency or the creation of a coordinating body within the existing regime to address the problems posed by a multiplicity of institutions. Whatever arrangement is selected will influence the form of legislation to be adopted.

Conformity of existing legislation with international instruments

At this stage, the inventoried existing legislation must be examined to ascertain whether it conforms to the provisions of the various international instruments. Gaps or inconsistencies would be noted for appropriate corrective measures in any proposed legislation.

For example, the Ghanaian legislation on plant protection, the Prevention and Control of Pests and Diseases Act, 1965, when examined in the light of the IPPC, reveals several shortcomings: the absence of provisions on international cooperation and exchange of information, risk analysis, exportation of plants and cooperation and coordination with the various institutions and bodies having responsibility for the control of invasive alien species. It is these shortcomings that are addressed under the proposed legislation, the Draft Quarantine Act.

It is worth noting that many of the international instruments are framework instruments, which provide in general terms the measures to be adopted by states for their implementation; others provide for specific measures for adoption. The IPPC, for example, enjoins parties to establish national plant protection organizations with specified functions (pest regulation, phytosanitary certification, importation and exportation regulations etc). If no national plant protection organization exists, therefore, it must be catered for under the proposed legislation.

Determination of form and content of legislation

Legislation is driven by several factors, including the political, economic and social circumstances of the state or entity. For the present discussion, the following factors are worthy of consideration:

In the preparation of the legislation, one of three identified approaches could be adopted:

In general, legislation on the control of invasive alien species would contain, among other things, the following:

The scope of the legislation is what the law covers and its stated objectives. This must be precise and concise; for example, “An Act for the prevention of the introduction and spread of pest of plants, plant products and related matters”.

The definition of terms could be adopted from the relevant instruments, especially the CBD and the IPPC. The IPPC’s definition of “pest”, for example, is wide enough to encompass invasive alien species.

The institutional or organizational basis for the control of invasive alien species could include provision for a plant protection organization and a board. The latter would serve as a technical advisory body to the minister on the implementation of the legislation. There could be a single institution or several institutions. Where no legislation exists on the subject, the IPPC model could be adopted. Where several institutions already exist to deal with the subject, it would be ideal to designate a lead ministry (e.g. agriculture) and to vest ministerial responsibility for the implementation of the Act in the minister. To ensure coordination and representation of relevant concerns and viewpoints, the composition of the board, however, could provide for representation from the range of agencies and stakeholders, including agriculture, trade and customs, transport, academic and research institutions, and farmers. A committee of the board could be established to deal with the avoidance of conflicts and overlaps where several institutions are involved.

The IPPC provides a list of functions for national plant protection organizations. These are useful guides on the subject. The list includes:

The legislation requires that enforcement provisions be made. These include:

Offences and penalties include penalties for convictions for violations on the basis of due process. Fines must be enough of a deterrent to prevent violations. Schedules to the Act could list prohibited items and items that may not be imported without certificates.

Financial provisions include the power to levy fees and financial autonomy for the NPPO.

Special procedures could include immunities for officials for acts done in good faith.

Appeal processes and procedures should be described.

The control of invasive alien species has international dimensions because the source of the problem is usually external. This calls for close international cooperation and collaboration, especially with neighbouring states. Provision should thus be made to cater for this requirement in the legislation, including the establishment of official contact points and pest reporting in accordance with the provisions of the IPPC and ISPM 7: Export certification system.

The legislation should include the power to make regulations. Provision should be made to give the minister or relevant authority power to make regulations to enable the law to meet changing circumstances or demands.

Capacity for implementation

Law does not operate in a vacuum. The best laws when enacted will not achieve the desired objective unless they are backed by adequate resources for their implementation. National capacity requirements for the implementation of the legislation would include:

Thus there is a requirement to provide the implementers of the legislation with the requisite resources, both human and material. This is a challenge for governments and policy makers. Where there is lack of capacity or resources for the implementation of the legislation, the steps to resolve the problem could include prioritizing, cost recovery, regional and subregional cooperation, and the sourcing of donor support or assistance. The financial mechanisms provided for under some of the global instruments such as the CBD and the SPS Agreement could be a source of assistance for developing countries. Similarly, technical assistance from FAO and the IPPC might also support the preparation and implementation of the legislation.


IMO. 1997. Twentieth IMO Assembly: Resolution A.868(20), adopted 27 November 1997: Annex - Guidelines for the control and management of ships’ ballast water to minimize the transfer of harmful aquatic organisms and pathogens (available at

IUCN. 2000. IUCN guidelines for the prevention of biodiversity loss caused by alien invasive species. Approved by the 51st Meeting of the IUCN Council, Gland, Switzerland, February 2000 (available at

UNCED. 1992. Agenda 21. Rio Declaration on Environment and Development: Report of the United Nations Conference on Environment and Development, Rio de Janeiro, Brazil, 3-14 June 1992 (available at

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