Alien species are species that occur outside of their natural range and potential ability to disperse. They may have come to Norway with the active or passive help of people, or on their own.

Alien species are divided into two groups: a) species that are able to reproduce in Norway (1180 species in 2012) and species that cannot reproduce here (1140 species in 2012).

The first group may pose a risk to Norway’s native biodiversity. As a result, all of the 1180 species in this group were impact-assessed for “Alien species in Norway – with the Norwegian Black List 2012.”

The following species have been evaluated:

  1. Species that have been intentionally released.
  2. Species that have escaped from captivity or farming, or species that have escaped from cultivation/breeding or from industrial activities.
  3. Species that have come as stowaways during the transport or movement of people, animals, plants and goods.
  4. Species that have spread from wild populations in neighbouring countries where the origin of the species is from 1, 2, or 3
  5. Species with unspecified anthropogenic origin where not enough is known about how the species arrived in Norway.
  6. Some subspecies of vascular plants that meet the requirements described above.
  7. Some species which have not yet arrived in Norway but is expected to arrive in the near future (named “door knockers”).

Species and organisms that are not evaluated

The method also clearly describes species that do not need to be evaluated.

These are:

  1. Native species that are spreading to new areas within the country’s borders due to human activity.
  2. Species that are imported to Norway, but that already have native populations.
  3. Propagated native species spread in Norway, including genetically modified organisms (GMOs) and genetic variants.
  4. Subspecies or lower taxa (except vascular plants).
  5. Single-celled organisms.