A crayfish in different colors.
The signal crayfish (Pacifastacus leniusculus) - an invasive species in Sweden. Photo: Ann-Katrin Hallin.

Swedish Crayfish Database

Page reviewed:  31/03/2025

Welcome to the national database for freshwater crayfish in Sweden. Here you can find information about occurrences of noble and signal crayfish, crayfish monitoring, and pest-infected waters.

The Department of Aquatic Resources is the data host for fish and crayfish on behalf of the Swedish Agency for Marine and Water Management. In the crayfish database, we store quality-assured data about crayfish in Sweden, where the data can be linked to vectorized and raster map layers. All data is available to the public.

Visit the Swedish Crayfish Database

 

We are collecting Sweden's crayfish occurrences

SLU collaborates with regional and local authorities, fishing organisations, and fishing water owners. The Crayfish Database also accepts and stores your data about crayfish, if you send it to us. 

In the database, you will find

  • Occurrences of crayfish in Sweden
  • Crayfish monitorings
  • Sampling of commercial fishermen's catches
  • Crayfish plague-declared and plague-infected waters
  • Some crayfish data is classified by fishing water owners and is not available to the public.

Data for research, red lists, and ecological status

The database functions as a geographic IT support for environmental monitoring. The data is used in national evaluations, for example, in the assessment of the ecological status of our waterways and in the SLU Swedish Species Information Centre's list of threatened species. The data is also used for monitoring fish conservation measures, such as liming, the construction of fishways, and habitat restoration. Research projects also make good use of the crayfish database.

Referencing downloaded data 

The Swedish Agency for Marine and Water Management is responsible for coordinating water-related environmental monitoring in Sweden. When you publish environmental monitoring data from the crayfish database, you should indicate that they were developed within the framework of coordinated Swedish environmental monitoring.

Data from the national crayfish database should be referenced as follows:  
Bohman, P. (Editor). yyyy. National Crayfish Database. Swedish University of Agricultural Sciences (SLU), Department of Aquatic Resources. http://www.slu.se/kraftdatabasen [yyyy-mm-dd]. 

Read more

Data hosting at SLU – environmental monitoring data for fish in lakes, rivers, and coastal areas.

Information about national data hosting on the Swedish Agency for Marine and Water Management's website (in Swedish).

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