Risk assessment of alien species

Rabbit. Photo: Marko PesuSome alien species can be classified as harmful. Invasive alien species may cause damage to the environment, economy or society. When determining the degree of harmfulness of invasive alien species and assessing the harm caused the tool used is a so-called risk assessment. Risk assessment facilitates activities such as the correct dimensioning of combating measures in relation to the risk caused by the species in question.

Risk is generally perceived as the probability of any adverse event and its impacts on the economy, the environment and health, for example. Risk is therefore intrinsically linked to both the probability and consequences of an event. An adverse event could be, say, an invasion by an alien species. To support decision-making, it is possible to assess the level of risk through a risk assessment.

Risk assessment is a scientific process consisting of the systematic identification and description of a hazard, an estimate of the exposure to it and a description of the risk involved. In this context, exposure means the probabilities and magnitude of the alien species’ entry, establishment and spread throughout the country and the related impacts.

Examples of different risk assessments related to alien species include:

  • Prioritisation of harmful species by way of a rapid risk assessment
  • Risk assessment of species already occurring in Finland
  • Risk assessments of species not occurring in Finland but susceptible to unintentional introduction
  • Risk assessments of species not occurring in Finland but subject to intentional translocation
  • Risk assessment of an individual pathway for spreading
  • Risk assessment of an individual company or industry
  • Risk assessment of a single policy measure

Risk assessment involves close interaction with risk management. Risk analysis consists of forming an idea of the risk (risk assessment), communicating this to the actors involved (risk communications) and managing the risk through means such as legislation, monitoring, voluntary action or licensing terms (risk management).

Risk assessment may be quantitative or qualitative. The results of quantitative risk assessment are given as numeric values, while a qualitative risk assessment is essentially verbal, though it may include quantitative components (numerical values or mathematical methods). Risk assessment may include consideration of the most cost-effective and feasible control measures.

Links to domestic and international risk assessments: