A close-up of a perch (Perca fluviatilis) swimming in a greenish aquarium. The fish's characteristic dark stripes and red fins are clearly visible. In the background are blurred plants and two other perch.
Perch (Perca fluviatilis). Photo: Mark Harris

Fish monitoring in lakes – NORS

Page reviewed:  28/03/2025

Welcome to the database for fish monitoring in lakes. Here you can download data from approximately 10,000 fish surveys conducted across about 3,900 lakes. You will also find guidance for those involved in environmental monitoring using lake fish sampling as a method.

The database for fish monitoring in lakes is officially called the National Register of Fish Monitoring in Lakes (NORS) and is the national database for lake fish survey data, in use since 1992. All data is publicly available. We deliver quality-assured data from fish surveys within national and regional environmental monitoring and liming programs. With our efforts, the world gains quicker access to the latest results. 

Download data from NORS

Data for research and national and regional evaluation

The database mainly consists of data collected through national and regional environmental monitoring programs. We also accept fish sampling data from surveys conducted by universities, municipalities, fisheries management areas, and other commissioning parties, with the goal of expanding the database in terms of geography and different types of lakes.

Data is used, for example, in national evaluations, when assessing the ecological status of our lakes based on fish populations, as reference material for local and regional fish survey studies, and in research projects.

Referencing downloaded data 

The Department of Aquatic Resources is the data host for fish on behalf of the Swedish Agency for Marine and Water Management. The Swedish Agency for Marine and Water Management is responsible for coordinating water-related environmental monitoring in Sweden. When publishing environmental monitoring data from NORS, you should state that it was produced as part of the coordinated Swedish environmental monitoring.

Data from NORS should be referenced as follows:  
National Register of Fish Monitoring in Lakes – NORS. yyyy. Swedish University of Agricultural Sciences (SLU), Department of Aquatic Resources. http://www.slu.se/sjoprovfiskedatabasen [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).

Water quality - Sampling of fish with multi-mesh gillnets (Swedish Institute for Standards, SIS).

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