Non-native species: code of practice

2. Your Responsibilities

Summary

Why control non-native species?

Non-native species can:

• damage or displace native species
• disrupt ecosystems
• spread diseases which affect native species
• interfere with our rivers, leading to increased flooding
• cause damage to buildings and infrastructure
• pose human health risks.

Many factors can influence how a non-native species behaves once it is introduced to a new ecosystem and in many cases it is impossible to predict the effect it will have. Since climate is one of those influencing factors, climate change introduces an additional level of uncertainty when attempting to predict the behaviour of a new species.

How do we control non-native species?

The Scottish Government's approach to non-native species is guided by a three-stage hierarchical approach:

What laws govern the introduction of non-native species to Scotland?

The principal legislation is the Wildlife and Countryside Act 1981 (the 1981 Act). More recent legislation has amended, updated and strengthened the 1981 Act.

The 1981 Act contains provisions on

• release or planting of all non-native species ^[8]
• keeping of invasive species ^[9]
• sale of invasive species ^[10]
• notification of invasive non-native species ^[11]
• Species Control Agreements and Species Control Orders ^[12] .

The 1981 Act includes a number of offences relating to the list above, some subject to a defence of having taken all reasonable steps and exercised all due diligence to avoid committing the offence.

What are my responsibilities?

Adopt a precautionary approach - if in doubt don't release or plant until you have a clear understanding of the situation.

• Carry out risk assessments - due diligence is likely to include assessing the risk of an offence happening, establishing how to avoid it happening and acting according to best practice to prevent it happening.
• Seek advice and follow good practice - seeking advice may be particularly important in establishing the native range of a particular plant or animal. This Code contains some good practice guidance and this is designed to help you to take reasonable steps and exercise due diligence.
• Report the presence of non-native species - reporting the presence of a non-native plant or animal can help the relevant organisation (see Chapter 10) to take earlier and more decisive action.

The need to control non-native species

2.1 This Chapter explains why we need to be concerned about non-native animals and plants, and describes your responsibilities in relation to non-native species.

2.2 Non-native species are plants and animals which have found their way to a new habitat through human activity. Many non-native species have been carefully managed and these contribute positively to our lives, for example as livestock, crops, timber, garden plants or pets.

2.3 Some non-native species have been deliberately or accidentally introduced to Scotland, from locations across the world. In other cases, species native to parts of Scotland have been moved to locations where they did not previously occur. These species are also non-native in their new locations. Although many of these have become established in small numbers and do not currently pose a threat, a small number are invasive.

2.4 In certain regulated circumstances ^[13] former natives may be reintroduced however, in many cases the environment into which the species is being reintroduced has changed since its extinction. These changes require reintroductions to be carefully planned and their impacts on the natural environment, land use and people to be considered and monitored. The Scottish Government follows the International Union for Conservation of Nature ( IUCN) Guidelines for Re-introductions http://www.iucnsscrsg.org/policy_guidelines.html. No-one is permitted to reintroduce former native species without the relevant authority.

2.5 Uncontrolled, these non-native and former native species can:

• damage or displace native species
• disrupt ecosystems
• spread diseases which affect native species
• interfere with our rivers, leading to increased flooding
• cause damage to buildings and infrastructure
• pose human health risks.

2.6 Non-native species sometimes expand rapidly because they have advantages over our native species - they might be more adaptable than, able to breed faster than or able to outcompete our native species. When they arrive in a new country, they have left behind the predators, parasites, diseases or competition that keep their numbers under control in their original location. Non-native species may only become a serious problem some time after their introduction. It is not always possible to predict which non-native species are invasive, which is why it is important that we maintain the principle of preventing the introduction of all new non-native species.

2.7 Controlling invasive non-native species once they become widespread is frequently very expensive. The most cost-effective way of dealing with the problems created by non-native species is to prevent these plants and animals from becoming established in the first place. If they have just become established, the need is to rapidly control or remove them before they become a widespread problem.

2.8 The 2010 report The Economic Cost of Invasive Non-Native Species on Great Britain ^[14] provides five case studies to illustrate how the cost of eradicating invasive non-native species increases considerably with the length of time that a species has been established in the country. For example, the early eradication costs of creeping water primrose ( Ludwigia peploides) which is currently established at 13 locations are estimated to be £73,000, whilst if it spread to a suitable habitat it is estimated that it could cost almost £242 million.

Managing the threat posed by non-native species

2.9 The Scottish Government's approach to non-native species is guided by the internationally recognised three stage hierarchical approach, the key principles of which are:

Prevention - preventing the release of all non-native species (both known invasive or otherwise) into the wider environment should be given the highest priority as the most effective and least environmentally damaging intervention.

Rapid response (eradication) - where prevention fails, early eradication or removal from the environment should be the preferred response.

Control and containment - once a species has become widely established, full-scale eradication is only possible or cost effective in a minority of cases. However, if non-native species are having serious negative impacts then it may be desirable to control or contain the population, or mitigate those impacts.

2.10 This approach is supported by provisions in the 1981 Act which place responsibilities on individuals and organisations regarding how they control and manage non-native species. The legislation also enables certain organisations to require the taking of emergency and other control measures for non-native species (see Chapter 9). Other legislation that is not covered by this Code may also support the three stage hierarchical approach (see the Annex for other relevant legislation).

2.11 Preventing the release of all non-native animals, and the planting of any non-native plants in the wild is critical to a successful policy on invasive non-native species. This is because it is not always possible to predict with certainty which species are invasive and because small populations of non-native plants and animals may be present for many years before 'taking off'. For example, Japanese knotweed was in this "lag phase" for nearly 100 years, as demonstrated by the graph in figure 1.

Figure 1: The Lag Phase of Japanese knotweed from, Child, L. and Wade, M. 2000. The Japanese Knotweed Manual. Packard Publishing Limited, Chichester.

2.12 Many non-native plants and animals that are currently established at low population levels may still be in their lag phase.

2.13 Because of the issues outlined above and the practical difficulties and costs associated with controlling invasive non-native species once they are established, preventing establishment is given the highest priority.

2.14 Preventing the introduction of non-native species is preferable to waiting to see if they are invasive, which leads to expensive control programmes designed to mitigate their damaging impacts. This is the approach advocated though the Convention on Biological Diversity and promoted through the Invasive Non-Native Species Framework Strategy for Great Britain.

2.15 Some habitats or locations are especially vulnerable to the introduction of non-native species. Severe impacts of non-native species on native biodiversity have occurred on remote islands where the native flora and fauna is less diverse, more isolated and therefore more susceptible to invasion. Other especially vulnerable habitats can, for example, include those found in marine, freshwater, riparian and woodland environments. Extra vigilance and caution should be exercised in and around these habitats.

2.16 Climate change is likely to have a significant impact on biodiversity in future years. It may enable more non-native species to establish and some that currently appear benign to become invasive.

2.17 It is likely that as the climate changes, the 'climate space' - the area which is climatically suitable - for each species or habitat will move (usually northwards or to higher altitudes in response to warming). In fact there is already some evidence of animals now occurring outside their former range (such as butterflies and marine molluscs).

2.18 However, these issues are very complex and it is not certain exactly how the climate will change, what its impacts will be on 'climate space' and how species will respond.

2.19 As the climate changes, some plants and animals may not be able to migrate successfully to new climate space and would require active intervention to translocate them to new areas to ensure their survival and the survival of the habitats and ecosystems of which they are a part. Non-native species legislation provides the necessary flexibility to regulate appropriate interventions of this type. If translocation does prove necessary it would be carried out under licence ^[15] .

The legal position and due diligence

2.20 This Code outlines the law relating to native and non-native species, including former native species and invasive non-native species. The principal legislation is the Wildlife and Countryside Act 1981. More recent legislation, including the Wildlife and Natural Environment (Scotland) Act 2011, has amended the 1981 Act. The 1981 Act now contains sections on the release or planting of all non-native species and the keeping, sale and notification of invasive species, in addition to provisions on Species Control Agreements and Species Control Orders. The Chapters that follow in this Code explain the main provisions set out in the 1981 Act.

2.21 It is important to note that the release or planting, keeping and sale offences in the 1981 Act are strict liability offences. This means that the prosecution does not need to prove any intention, knowledge, recklessness or negligence on the part of the accused. It is enough for the prosecution to prove that the offence took place - so if you are in any doubt regarding whether an animal or plant is native, don't release or plant.

2.22 However, a person accused of a release, planting or keeping offence may successfully establish a defence if they can show that they took all reasonable steps and exercised all due diligence to avoid committing the offence. This due diligence defence is designed to recognise efforts made by people to comply with the legislation. Ultimately it is always a matter for the Court to determine whether the defence of due diligence has been established. This will depend on the circumstances of each particular case but compliance or non-compliance with the Code could be used as evidence in a criminal prosecution.

2.23 This Code of Practice outlines the law and, where appropriate, gives practical guidance on what reasonable steps might be taken, and how due diligence may be exercised, in relation to the release, planting or keeping offences. Exercising due diligence is likely to involve assessing the risk of an offence happening, establishing what precautions to take to avoid the offence happening and regularly reviewing the risk, the precautions and their suitability. Doing nothing is unlikely to protect an accused; positive action is likely to be required. The type and extent of action required to satisfy the Courts will vary from case to case depending on the individual relevant circumstances.

2.24 The Code also outlines behaviour which is considered to be best practice and which may help to prevent an offence happening. Not abiding by best practice will not in itself be an offence but evidence of a failure to abide by best practice outlined in the Code could be used as evidence in a criminal prosecution.

Your responsibilities

2.25 The Code outlines the law, but it is important to note that independent legal advice should be taken as needed. In practice, though, acting reasonably and responsibly is prudent. This involves:

Adopting a precautionary approach: If you are in any doubt that your intended actions might lead to the release or planting of a non-native species then you should take the precautionary approach; don't release or plant until you have a clear understanding of the situation.

Carrying out risk assessments : Due diligence is likely to include assessing the risk of an offence happening, establishing what to do to avoid it happening and acting according to best practice to prevent it happening. Further advice and information, including identification guides, can be found at the GB Non-Native Species Secretariat website: www.nonnativespecies.org.

Seeking advice and following good practice: You should seek advice from an expert if you are unsure about any issues relating to the release or planting, keeping, sale or notification of non-native plants and animals. This may be particularly important in establishing what the native range is of a particular plant or animal. A list of suggested contacts is provided in Chapter 10. More information about the 1981 Act and other issues relating to non-native species can be found at: www.scotland.gov.uk/nonnativespecies. This Code contains some good practice guidance and this is designed to help you to take reasonable steps and exercise due diligence.

Reporting the presence of non-native species: The cost of removing or controlling a well-established invasive non-native plant or animal can be very high. Reporting the presence of a non-native plant or animal can help the relevant organisation (see Chapter 10) to take earlier and more decisive action.