Invasive Non-Native Species (INNS) are one of the major causes of biodiversity loss and can have profound environmental, economic and social impacts. It may be a criminal offence (external link) to spread invasive non-native plants (external link) and animals (external link).

Managing INNS is a critical part of Local Nature Recovery Strategies (LNRS) and Biodiversity Net Gain (BNG) projects. Urban areas tend to be particularly impacted by INNS and improving connectivity between these areas can inadvertently spread them further. It’s essential that work on habitats is undertaken in a biosecure manner and appropriate management ensures that it is the native species that benefit from the intervention.

There is a network of Local Action Groups (LAGs) that seek to manage the INNS that impact their communities and local environment. LAGs often use volunteers to manage INNS, providing social prescribing benefits and creating opportunities for residents to participate in the improvement of their environment. Many INNS management projects have suffered from short-term funding, resulting in the vestigial populations of INNS recolonising the site and providing only short-term benefits for the project. BNG is different and has the potential to deliver a lasting legacy for habitats.

When developing strategies and projects it is essential that:

1. Any known records of INNS are reviewed and the risk for these INNS spreading further are considered. Sites should be surveyed for unrecorded INNS. Site operators need to be able to recognise the INNS present. Plans should include provision to eradicate INNS to improve the quality of the habitat or prevent the population from spreading further.
2. Be aware that some INNS populations harbour diseases that can have a devastating impact on native communities. For instance, many urban lakes and ponds host exotic amphibians released from the pet trade that carry fungal diseases. Consider the disease risk from INNS, as well as the risk of INNS themselves.
3. Work should be undertaken in a biosecure manner. Landscaping and soil movement should consider the risk of spreading propagules. Staff, contractors and volunteers involved in the project should be made aware of ‘check, clean, dry’ and have access to biosecurity facilities such as washdown areas, pressure washers and boot cleaning stations.
4. Habitats that are in transition are particularly vulnerable to invasion. Provision must be made to respond rapidly and effectively to the appearance of INNS in restored or newly created habitats.
5. Completed schemes will require regular monitoring to ensure that INNS don’t establish. Project managers might consider using citizen science to monitor for potential future INNS and a legacy agreement with a local action group to eradicate new invasions, where possible.

Additional sources of information:

• River basin management plans, updated 2022: summary programmes of measures – mechanisms - 10. Invasive non-native species (INNS) - Guidance - GOV.UK (www.gov.uk)
• Invasive non-native (alien) plant species: rules in England and Wales - GOV.UK (www.gov.uk)
• Invasive non-native (alien) animal species: rules in England and Wales - GOV.UK (www.gov.uk)
• Preventing the release into the wild of certain plants and animals: guidance - GOV.UK (www.gov.uk)