Risk assessment

Risk assessment is used to assess the risk of a non-native species entering, establishing, spreading and causing impacts in GB.  These pages provide information on GB risk assessment scheme developed and used in GB.  Completed risk assessments are also posted here.  

Risk assessment is a key tool in the armoury against invasive non-native species.  It can be used to aid prioritisation, to help enable effective rapid responses and for underpinning decision-making.  The Non-native Risk Assessment (NNRA) scheme was established in December 2006 (Baker et al 2008 (external link), Mumford et al 2010 (PDF)).  Within this scheme risk assessments on non-native species are carried out by independent experts, which are then reviewed by one peer reviewer and GB's independent panel of risk analysis experts (known as the NNRAP).  Following this process risk assessments are available for comment before being finalised.


Common misconceptions about risk assessments:

To address a number of common misconceptions about non-native species risk assessments, the following points should be noted:

  • Risk assessments consider only the risks posed by a species. They do not consider the practicalities, impacts or other issues relating to the management of the species. They therefore cannot on their own be used to determine what, if any, management response should be undertaken.
  • Risk assessments are advisory and therefore are part of the suite of information on which policy decisions are based.
  • Completed risk assessments are not final and absolute. They are an assessment based on the evidence available at that time. Substantive new scientific evidence may prompt a re-evaluation of the risks and/or a change of policy.


For those undertaking risk assessments:


Period for comment

The risk assessments that have completed the process are available from these pages.  They are open for stakeholders to provide comment on the scientific evidence which underpins them for three months from the date of posting on this website (to send in your comments contact us). 

If you require an accessible version of a risk assessment please

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with the following:

  • the risk assessment required 
  • your name and email address
  • the format you need, for example, audio CD, braille, BSL or large print, accessible PDF
We’ll consider your request and get back to you in 15 working days.

If you would like to be informed when new risk assessments are put online, contact us contact us and ask to be put onto the risk assessment alert e-list.


Risk assessments (PDFs)

Contact us to submit your comments on the risk assessments.


Other Risk Assessment Schemes

The European and Meditteranean Plant Protection Organisation (EPPO) carries out pest risk analysis at the European and Mediterranean scale. Find risk analysis for plant pests (external link) and risk analysis for invasive plants (external link).

The Aquatic Species Invasiveness Screening Kit (AS-ISK (external link) has been developed by Cefas and colleagues to support the identification and management of invasive non-native aquatic species (Copp et al. 2016 (external link)) and has been applied to a wide range of taxa (Vilizzi et al. 2019 (external link)).


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