Invasive Non-Native Species Group

The overarching aim of the group is to minimise risk and reduce negative impacts caused by invasive non-native species in Wales.


  • To co-ordinate the response of all relevant sectors in Wales to the environmental, social and economic challenges presented by invasive non-native species.
  • To provide a forum where policy on invasive non-native species in Wales can be developed and lead responsibilities agreed.
  • To promote the integration of policy and practice across the public sector and other sectors, and provide a framework for action, in particular identifying requirements for advice and research.
  • Contribute to and support wider action on invasive non-native species at GB level.
  • Contribute to and support action on invasive non-native species at a local level in Wales.

GB Invasive Non-native Species Strategy

The GB INNS Strategy provides a framework on how to minimise the risks posed by invasive non-native species. The strategy sets out the key aims and actions to deliver a co-ordinated approach for addressing the threats posed by invasive non-native species.

  • get people to work better together, including the government, stakeholders, land managers and the general public
  • improve co-ordination and co-operation on issues at a European and international level

The strategy covers 2015 to 2020 and replaces the first strategy published in 2008

Himalayan Balsam

Invasive non-native species

Invasive non-native species of flora and fauna are considered the second biggest threat after habitat loss and destruction to biodiversity worldwide and the greatest threat to fragile ecosystems such as islands. Because of the increase in the global movement of people and goods, they pose a growing problem in the conservation of biodiversity, and are a threat to economic interests such as agriculture, forestry and fisheries. The true extent of the threat posed by invasive non-native species has become much better understood in recent times, including an appreciation of the fact that past introductions have usually occurred with little awareness of the potential consequences.

There are a number of groups active in Wales tackling invasive species including the Dee Invasive Non-Native Species Project. The project is a catchment-wide partnership initiative which aims to coordinate the control and monitoring of invasive non-native species (INNS) within the Dee catchment to ensure a joined up approach to INNS management is delivered.

Asian shore crab: First UK sighting in Glamorgan

Asian Shore Crab (Hemigrapus sanguineus) has been recorded for the first time on mainland UK, on shore at Aberthaw, Vale of Glamorgan on 2nd May. As this species has only been recently found in the UK, a high level of vigilance is important. For identification assistance and for reporting a sighting please visit the Marine Biological Association website

  1. Asian shore crab ID and fact sheet (pdf)

Chalara dieback of ash

Chalara dieback of ash is a serious disease of ash trees caused by a fungus called Chalara fraxinea.The disease causes leaf loss and crown dieback in affected trees, and it can lead to tree death. Outbreaks in Ash have been reported in the wild in East Anglia and in various parts of the UK from tree nursery stock originating in Buckinghamshire.

Chalara dieback in Wales

There are now 10 confirmed cases of Chalara fraxinea in Wales: A small new planting site in Carmarthenshire, 5 new planting sites in Welsh Government woodlands in the Wye Valley; a small new planting in Caerphilly, a small new planting at Llanwern High School in Newport, a planting scheme at Glynllifon College in Gwynedd and a new planting scheme at Betws y Coed. Most of the young trees from these sites have been lifted and destroyed.

Future management actions:

  • Provide advice on management of mature infected ash trees.
  • Identify mature ash that are resistant to the disease and could be used to propagate and develop new strains of ash to restock woodlands.
  • Investigate woodland management and forestry techniques that could help slow down the spread of the disease and lessen its impact.
  • Continue to survey in towns, cities and in the countryside surrounding infected sites.
  • Any sites where trees display possible symptoms of Chalara will be logged and revisited for samples to be taken for laboratory diagnosis.

    1. Further information and guide to symptoms
    2. Chalara dieback of Ash briefing (pdf)

    Invasive Plant Tracker

    An on-line invasive plant tracker tool is now available. You can download the free App (PlantTracker),which allows you to take a photo of the plant in the wild with your smart phone, and upload the image (and location automatically) to a central database. If you don't have a smartphone, you can also use the website. On the website there is also a map which shows you the current (uploaded) distribution of each species. It is very easy and quick to use, and your data get verified and sent to the NBN.

    ‘Alarm list ‘of potentially invasive non-native aquatic species to Great Britain

    The alarm list has been compiled by the UK Technical Advisory Group Alien Species Group using data from a range of sources, and in the light of comments and suggestions from external reviewers. Its aim is to encourage reporting of any species listed to the relevant authorities and thus provide an opportunity for appropriate action to be taken. The species listed are those thought to pose a risk to surface waters and their ecological status under the EC Water Framework Directive, but whose presence has not yet been recorded in Great Britain.

    1. Alarm List

    Species in Wales

    Amphibians & Reptiles



    Terrestrial Mammals



    Helping Wildlife

    Wildlife Gardening