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Import and keep of crustaceans in freshwater aquaria – risks posed to biodiversity in Norway

Ordered: 20.03.2020

Report no:

Publishing: 15.01.2021


Key message:

What are the risks associated with importing and keeping freshwater crustaceans regarding their establishment in Norway and the introduction and spread of pathogens to the red-listed (vulnerable) native crayfish?

The Norwegian Environmental Agency has commissioned the Norwegian Scientific Committee for Food and Environment (VKM) to assess the risks associated with import and keeping of crustaceans in freshwater aquaria.

This assessment has been commissioned due to increased interest in the import of freshwater crustaceans for private acquarium enthousiasts. The main interest is in freshwater crayfish, but crabs and shrimps are also of interest.


VKM will first determine the range of species currently being kept in Norway, and which species are likely to be of interest in the years to come. VKM will then assess the risk these species pose to biodiversity in Norway, and especially to the endangered native crayfish. The assessment will evaluate the risk of alien species establishment in Norway from now to 2100, and the risk of the introduction and spread of foreign pathogens.

Risk to the noble crayfish

The noble crayfish (Astacus astacus) is the only native species of freshwater crayfish in Norway. It is severely threatened following the introduction of the signal crayfish (Pacifastacus leniusculus), a carrier of the crayfish plague.

An important part of the project will be to identify species with characteristics similar to the signal crayfish, which can outcompete the noble crayfish and possibly introduce new detrimental diseases.

The project group

The project group consists of:

  • Gaute Velle, the VKM Panel on Alien Organisms and Trade in Endangered Species (CITES) (Academic leader of the project).
  • Trude VrålstadPDF, external expert from the Norwegian Veterinary Institute
  • Stein Ivar Johnsen,PDF external expert from the Norwegian Institute for Nature Research (NINA)
  • Charlotte EvangelistaPDF, external expert from the University of Oslo
  • Lennart EdsmanPDF, external expert from the Swedish University of Agricultural Sciences (SLU)
  • Martin Malmstrøm, VKM Secretariat (Project manager).

The VKM Panel on Alien Organisms and Trade in Endangered Species (CITES) is responsible for the risk assessment. The assessment is scheduled for publication in January 2021.


The Norwegian Scientific Committee for Food and Environment

T: 21 62 28 00

P.O. Box 222 Skøyen
0213 Oslo

Webmaster: Tanya S. Kristiansen
Senior Editor: Ingrid M. Høie