Invasive species Contents


Invasive non-native species (INNS) are one of the top five threats to the natural environment. They cost the economy £1.8 billion per year, yet the Government is not providing the funding needed to tackle the threat.

INNS are those that have moved outside of their natural range and negatively affect native biodiversity, ecosystem services and public health, through predation, competition or by transmitting disease. The number of INNS in the UK and its Overseas Territories is among the highest globally and is growing with the expansion of international trade, transport and travel. Around 40 invasive species are expected to become established in the next 20 years in Great Britain and preventing this from happening must be a top Government priority.

It is hundreds to thousands of times cheaper to prevent invasive species from establishing, rather than tackling them once they are established. Biosecurity and closing pathways are critical first lines of defence to prevent the introduction of INNS. Expenditure on biosecurity in Great Britain is approximately £220 million per year, yet invasive species only receive 0.4 per cent of that sum (£0.9m). While the Government’s GB-wide working and Non-Native Species Secretariat is highly regarded, its funding does not match the scale of the challenge. We recommend that its funding is significantly increased to at least £3 million a year.

We support the Government’s latest focus on pathways and prevention, but for it to be effective, there needs to be a step-change in awareness, so that the public can assist in preventing the introduction of species, spot likely invaders and aid eradication efforts. The Government should update and enhance its biosecurity public awareness campaigns and put significantly more resources into engaging members of the public, replicating the approach taken in New Zealand, by training at least two per cent of the population (1.3 million) biosecurity volunteers. This ‘biosecurity citizens’ army’ would be a huge boost to the UK’s resilience to climate change and add significant people power to the fight to eradicate priority invasive species. The Government should also undertake a review of Local Action Groups to identify best practice and enhance their coordination through the Non Native Species Secretariat.

The example of the invasion of oak processionary moth, now established in Greater London from imported oak trees, highlights the importance of swift biosecurity and trade restrictions. We welcome the introduction of DEFRA’s monthly biosecurity meetings to identify future threats, but action has been too little, too late. The Government needs to ensure that with problem species are identified and banned from import before they present a risk to the UK. To improve biosecurity at the UK’s borders and tackle the risks from increased online trade and new trade routes, we recommend that a dedicated inspectorate is established, with similar funding to other such inspectorates.

Invasive plant pathogens are of increasing concern. For example, ash dieback is caused by a non-native fungus and is estimated to cost £15 billion over the next 100 years. Yet pathogens they are not included within the remit of the Invasive Non Native Species Strategy. Given the large threat they pose to the environment and economy, we recommend that the next Invasive Non Native Species Strategy includes invasive pathogens since the methods of prevention and control are broadly similar. We recommend that a rapid response emergency fund is established for agencies when they need short term funding to tackle a threat and avoid species spreading out of control, as should have happened when oak processionary moth first arrived in the UK in 2006.

The UK Overseas Territories (OTs) are home to 90 per cent of the UK’s biodiversity and the introduction of invasive species has been recognised as the biggest threat to island biodiversity and caused numerous extinctions. The UK Government funds a range of projects and programmes in the OTs, including infrastructure developments to improve their accessibility and increase tourism. Increased accessibility increases the risk of introducing invasive species. Construction projects have resulted in the introduction of invasive species, such as fire ants in Montserrat. Many of the OTs lack biosecurity legislation and we recommend that this must be established and resourced to ensure that each OT has up to date biosecurity legislation and adequate powers of enforcement by the end of 2020.

Large scale projects to eradicate invasive species, such as those to remove deer and rats from South Georgia, present huge opportunities to restore rare and unique wildlife. Yet these projects are costly and have been largely privately financed in the past. The Government should consider implementing a system to match-fund contributions from private partners for large scale eradication projects where there can be the greatest wins for biodiversity.

Published: 25 October 2019