Convention on the Conservation of European Wildlife
and Natural Habitats

Standing Committee

Recommendation No. 57 (1997) on the introduction of organisms belonging to non-native species into the Environment

(Adopted by the Standing Committee on 5 December 1997)

The Standing Committee of the Convention on the Conservation of European Wildlife and Natural Habitats, in accordance with Article 14 of the Convention,

Having regard to the aim of the Convention which is notably to ensure the conservation of wild flora and fauna, by giving particular attention to species, including migratory species, which are threatened with extinction and vulnerable;

Recalling that under Article 11, paragraph 2.b of the Convention, each Contracting Party undertakes to strictly control the introduction of non-native species;

Considering that species native to a given territory means a species that has been observed in the form of a naturally occurring and self-sustaining population in historical times; “species” in the sense of this Recommendation refers both to species and to lower taxonomic categories, subspecies, varieties, etc. (thus, for instance, the release of a different non-native subspecies into a given territory should also be considered as an introduction);

Considering that “introduction” means deliberate or accidental release, into the environment of a given territory, of an organism belonging to a non-native taxa (species or lower taxa that has not been observed as a naturally occurring and self-sustaining population in this territory in historical times);

Considering that this Recommendation does not apply to:

–          genetically modified organisms,

–          the introduction of non-native plants cultivated in managed agricultural and forest areas or for the purpose of combating soil erosion,

–          the introduction of non-native organisms belonging to non-native species used for the purposes of biological control, if the introduction has been authorised on the basis of regulations for plant protection and pest control, which comprise an assessment of the impacts on flora and fauna,

–          the introduction of non-native species maintained into confined space (for example, botanic gardens, greenhouses, arboreta, zoos, aquaculture or animal-breeding establishments or circuses),

–          or the use of birds of prey in falconry;

Considering that the introduction of organisms belonging to non-native species may initiate a process (competition with native species, predation, transmission of pathogenic agents or parasites) which can cause serious harm to biological diversity, ecological processes or economic activities;

Being aware of the need to set up a system of risk management aimed at forestalling uncontrolled introductions and at reducing to a minimum the negative consequences of those it has been impossible to prevent;

Believing that the eradication of an established introduced species is very difficult and costly, and in many cases probably impossible;

Desirous of laying down a minimum number of rules, accepted and applied by everyone, aimed at anticipating and repairing the damage caused by inopportune introductions and which should be based essentially on principles of precaution and prevention, and referring to the "polluter-pays" principle;

Noting that there is a need to establish an international information and consultation mechanism to co-ordinate efforts directed at the prevention or eradication of harmful introductions;

Recognising that it is particularly difficult to mobilise the competent authorities and public, whenever an introduction does not endanger human health or major economic interests, and noting the consequent need for a vigorous policy of information and education concerning the problem and the ecological consequences thereof;

Bearing in mind Recommendation No. R (84) 14 of the Committee of Ministers of the Council of Europe to Member states on the introduction of non-native species, adopted on 21 June 1984;

Recalling that under Article 8.h of the Convention on Biological Diversity, each Party undertakes to prevent the introduction of, control or eradicate those alien species which threaten ecosystems, habitats or species,

Recommends that Contracting Parties:

1.         Prohibit the deliberate introduction within their frontiers or in a part of their territory of organisms belonging to non-native species for the purpose of establishing populations of these species in the wild, except in particular circumstances where they have been granted prior authorisation by a regulatory authority, and only after an impact assessment and consultation with appropriate experts has taken place;

2.         Endeavour to prevent the accidental introduction of organisms belonging to non-native species into the environment with the potential to establish populations, where they use anthropogenic routes of dispersal;

3.         Draw up a documented national list of non-native species established in the wild, which are known to be invasive and/or cause harm to other species, ecosystems, public health or damage to economic activities;

4.         To consider, for the purposes of the application of the Convention, the suggested measures listed in the guidelines set out in the Appendix to the present Recommendation, as appropriate to the specific circumstances in their territory;

5.         Communicate to the Secretariat, so that it may in turn inform the other Contracting Parties, any relevant measures adopted or envisaged as well as any information available on the

outcome of the measures adopted.



            Measures that may be considered as appropriate for controlling introductions of non-native species are listed for consideration by Contracting Parties. Where appropriate, Contracting Parties are invited to take into account the provisions of existing international agreements and recommendations where they already address issues which are listed in these guidelines.

1.         Deliberate introductions into the environment

a.         Establishing, in application of the principles of precaution and prevention, a system for prohibiting deliberate introductions of organisms belonging to non-native species, and not granting exemptions save in exceptional cases. Whatever the circumstances, the prohibition should apply to the deliberate introduction of any organisms belonging to non-native species into the environment. Take particularly into consideration the vulnerability of ecosystems of islands, lakes, enclosed and semi-enclosed seas, or centres of endemism.

b.         Establishing a system of exemptions, or exceptional authorisations, based on the following provisions:

i.          the introduction of an organism belonging to a non-native species should only be considered if it benefits man and/or ecosystems;

ii.         the introduction of an organism belonging to a non-native species should only be considered if no native species is considered suitable for the purpose for which the introduction is being made;

iii.        no organism belonging to non-native species should be introduced into the environment, except for exceptional reasons and only if the operation has been preceded by a comprehensive and carefully planned impact study, which has reached a favourable conclusion on the proposal.

c.         Such an impact study should include:

i.          a taxonomic, ecological and ethological analysis;     

ii.         an analysis of the reproduction, feeding habits, dispersal or migration (if relevant), pathology, predators and competitors of the species to which the organism concerned belongs and of the risks of hybridisation with organisms belonging to native species;

iii.        an ecological analysis of the proposed host habitat (including, in particular, an assessment of the effects on the surrounding natural or semi-natural habitats of the introduction of any organisms belonging to species, sub-species or varieties of plant to artificial, arable, ley pasture, forest or other monoculture systems);

iv.        an appropriate assessment of measures to reduce or minimise negative effects;

v.         an analysis of the risks and dangers and of the means that could be used to eradicate or control the introduced population should unforeseen or harmful consequences of the introduction come to light.

d.         Defining with precision the statutory quarantine procedures applicable to imported non-native species for each of the main taxonomic groups, and informing the Secretariat of these statutory procedures where they exist.

e.         Once the introduction has been authorised but before the introduction takes place, carrying out trials in a controlled manner or, where possible, in a confined space.

f.          Introduction operations should only be carried out by officially recognised establishments and be subject to very strict health and safety requirements.

2.         Accidental introductions into the environment

2.1.      "Fugitives"

a.         Defining as “fugitives” organisms belonging to non-native species (or their descendants) that have been imported lawfully and set free, either accidentally or deliberately, but without the deliberate intention to populate.

b.         Limiting escapes by a very strict application of rules:

i.          preventing escape from establishments containing non-native wild plants (botanic gardens, greenhouses, arboreta and other types of plant culture), or where non-native wild animals are held in captivity (zoos, animal-breeding establishments, fish farms, etc.), by adopting measures to prevent such escape, which may include:

–          strict standards of security for boxes, cages, enclosures and for the transportation of species,

–          the strict control and containment in a confined space of species considered as a potential serious ecological danger in the event of their escape,

–          the requirement that all establishments keeping captive organisms belonging to non-native species should be licensed,

–          a register of and an appropriate system to mark animals so that their origin can be identified in the event of their escape,

–          strict rules in the event of the establishment closing down to prevent organisms from being deliberately or accidentally freed,

–          for the breeders of aquatic species, a location that rules out any communication with open water, bearing in mind the risk of flooding; ideally, such installations should never be located in an area liable to storm damage, even very exceptional climate events (in particular, floods every 100 or even 500 years);

ii.         since special attention must be given to aquariums because of the risks involved when they are emptied, imposing standards and procedures on public aquariums and on dealers in species used in aquariums;

iii.        since animals, plants or micro-organisms accompanying lawfully introduced organisms constitute another aspect of accidental introductions of organisms, in particular marine organisms, applying strictly the International Council for the Exploration of the Sea (ICES) Code of Practice on the Introductions and Transfers of Marine Organisms - 1994, which requires that only species of the first generation be set free, after a period of quarantine, and never species belonging to the stock initially imported; issuing a permit for the transport of captive-bred organisms which should be authorised only if the conditions in question are fulfilled;

iv.        as the use of live bait for fishing is another source of unintentional introductions, ensuring, by means of appropriate regulations covering the trade in and use of such live bait, that only organisms belonging to species present in the waters concerned are in fact used. It is important to safeguard the faunal and floral integrity of each drainage basin and thus not to introduce organisms belonging to species that are naturally absent from it, even if they come from neighbouring drainage basins in the same State;

v.         drawing up special rules to safeguard certain sensitive areas (protected areas, islands, areas recognised as having great biological diversity or containing endemic species) from escaped species, such as prohibiting establishments from keeping captive species in these areas or in their neighbourhood or subjecting such establishments to even stricter security conditions than elsewhere;

vi.        as the setting free of pets belonging to non-native wild species is a development of increasing concern, limiting as appropriate the species that may be offered for sale to ones that could not survive in the environment in the country concerned or, in so far as people travel with their animals, that could not survive anywhere in Europe. Failing or in addition to this, taking as appropriate the following measures: a general prohibition on setting these pets free; an obligation for pet merchants to inform their customers of this prohibition and of the penalties for violation; a recovery system for animals their owners wish to get rid of, which could be financed by a tax on sales; providing an incentive to use this system in the form of a refundable deposit; subjecting as appropriate animal dealers to the same rules as other enterprises keeping captive animals;

vii.       taking precautions that organisms belonging to non-native species intended for human consumption do not escape, alive, into the environment;

viii.      taking precautions that non-native cultivated forestry species or ornamental plants do not become propagated into the environment;

ix.        controlling the possession and transport of organisms belonging to non-native species and, provided that reliable criteria are available, prohibiting the possession of organisms belonging to non-native species liable to reproduce in the environment.

2.2.      “Stowaways”

a.         Defining as “stowaways”, organisms belonging to non-native species transported inadvertently from one country to another.

b.         Identifying all vectors of introductions and adopting effective preventive measures:

i.          increased inspections and the application of veterinary and plant health measures in regard to consignments of animals and plants and products thereof and the packaging used;

ii.         taking, as appropriate, preventive measures in respect of aircraft and ships arriving from exotic countries, in view of the fact that they represent another pathway for introductions, paying particular attention to water used as ballast.

3.         The control of introduced species

a.         Abolishing the legal protection enjoyed by certain species introduced without authorisation and giving them a special legal status so that the necessary control and eradication measures can be taken. In particular, steps should be taken to ensure that introduced species are not automatically protected by law when the latter applies to all the species belonging to a particular taxonomic group, in order to make it legally possible to control them (express reference should be made to “indigenous” species in lists of protected species).

b.         Preventing any consolidation of the genetic base and populations of such species into the environment and, if appropriate, facilitating the taking of any active measures of control or eradication required:

i.          prohibiting all further releases by publishing a list of animal and plant species already introduced without authorisation which it is forbidden to set free into the environment, and by regulating the possession and transport of such species in order to keep them in a confined area, thus minimising the risk of escape;

ii.         classifying species introduced without authorisation among those for which hunting or destruction is permitted at all times;

iii.        introducing an obligation to notify the authorities of the presence in the environment of unauthorised non-native species and attempting to eliminate them;

iv.        granting the authorities the power to declare an ecosafety emergency in order to attempt to eradicate species introduced without authorisation;

v.         empowering the administrative authorities to take eradication measures in the event of unlawful introduction;

vi.        adopting plans to control species introduced without authorisation by requiring landowners, local authorities and the central administration to introduce measures laid down in regulations to eradicate or limit the numbers of certain species or to safeguard natural areas, especially protected areas and their surroundings, from the intrusion of unauthorised non-native species.

c.         Preventing a species introduced without authorisation from spreading through the introduction of binding preventive measures: inspections, disinfection, the closing of certain areas to traffic, etc.

4.         Offences, penalties and civil liability

a.         Punishing illegal introductions, including those resulting from negligence.

b.         With a view to making illegal introductions easier to prove: making it compulsory to register and mark large captive animals so that their owner can be easily identified; and, for other species establishing a presumption;

c.         With regard to penalties:

i.          establishing criminal penalties for unlawful introductions of organisms belonging to non-native species and, where appropriate, making the authors of these introductions civilly liable (the penalties for unlawful introductions should be as severe as for the most serious offences against legislation on protection of the environment, such as certain types of pollution);

ii.         applying administrative sanctions against establishments that keep or breed organisms belonging to non-native species but do not take the necessary precautions to prevent their escape. These could involve the withdrawal of permits and the temporary or even permanent closing of the enterprise, and the confiscation of the organisms.

d.         With regard to reparation, and with reference to the polluter-pays principle:

i.          making the person responsible for the offence bear the cost of eradicating the species introduced without authorisation;

ii.         in the event of an escape, making the person responsible liable for the cost of the preparation and execution of a plan for recapture, control or eradication;

iii.        instituting a system of reimbursement of the expenses incurred for reparations, as well as the payment of compensation in respect of the damage caused to the environment;

iv.        setting up guarantee systems and insurance arrangements or compensation funds financed by professional species breeders or traders.

5.         National policies and institutions

a.         Framing a national public policy on the introduction of non-native species.

b.         Designating a specialised department within each competent authority with appropriate resources to prepare measures indicated in the present appendix and supervise their implementation.

c.         Consulting clearly identified scientific and other clearly identified competent authorities before decisions are taken on the introduction of organisms belonging to non-native species, reintroductions of organisms belonging to wild species, restocking and reinforcement of populations of organisms belonging to wild species in the environment, and possibly eradication.

d.         Constituting interministerial machinery to co-ordinate the action taken by the various authorities concerned and drawing up a national programme to reduce the risk of accidental introductions, rapidly identify newly introduced organisms belonging to non-native species and control ones that have become established in the wild without damaging the environment.

            With regard to aquatic species, for example, a commission composed of the various authorities concerned with continental waters and the oceans could be responsible for preparing a report identifying and assessing methods of reducing the risks associated with the introduction of organisms belonging to non-native species, which would also cover:

–          the identification, description and management of the risks entailed by the various possible types of introduction,

–          a decision making process for approving programmes to control introduced species,

–          research, in particular on past introductions, education and technical assistance.

6.         Information and co-operation

a.         Informing the general public of the ecological, economic and health hazards associated with introductions of organisms belonging to non-native species, and of the criminal and/or civil liability incurred by infringing the statutory provisions in force.

b.         Co-operating with neighbouring states or ones sharing a common coastline, whether or not they are parties to the Bern Convention, directly or through the intermediary of the Secretariat; consulting them on the measures that might be adopted, notifying them of deliberate introductions and informing them of accidental ones.

c.         Submitting an annual report to the Standing Committee on the application of this recommendation and in particular on introductions creating or liable to create a risk.