Kainuu fisheries research station


Enclosed Ecosystem Platform

Parent institution: Senate properties
Active since 1935
Active through all year

Fields of study

  • Climatology, Climate Change
  • Environmental sciences, Pollution
  • Oceanography, Fishery
  • Limnology

Contact Information

Hyvärinen, Pekka
email: pekka.hyvarinen@luke.fi

Kainuu fish hatchery, founded in 1935 by Varisjoki River flowing into Lake Oulujärvi was modernized in the 1990s and 2000s including not only a state-of-the-art aquaculture facility but also an outstanding selection of aquariums, pools and stream channels for experimentation. The research facility, covering an area of about 7 hectares, has been fully dedicated to experimental research purposes since 2005. The station enables extensive possibilities to carry out aquatic ecological, environmental or management-related research in laboratory and semi natural scale experimental arenas. Production scale fish farming experiments are also possible.

The research facilities include both indoor and outdoor set-ups of streams (12 + 6), indoor tanks (144), outdoor pools (50) and combined stream-pool systems (40). Video arrays and PIT-telemetry devices are available for observing and monitoring purposes. Water (max 750 l/s) for the streams and pools is taken from Lake Kivesjärvi (surface area 27 km2, mean water pH 6.7, oxygen 9.2 mgl-1, total P 17.0 ygl-1 and conductivity 3.5 mSm-1). All the devices are used throughout the year. Ice cover season in nearby lakes lasts from early November until mid-May. Combination of the above experimental devices and arenas with new technology monitoring systems and with production scales experimental fish farming possibilities makes the station unique for experimental aquatic ecology research in Europe. The strength of the research lies in close co-operation with other aquatic research facilities and fish farms of Natural Resources Institute Finland and in extensive co-operation with leading research teams in aquatic ecology in the Finnish universities of Eastern Finland, Oulu, Helsinki and Jyväskylä.

The Location

Country: Finland

Latitude: 64.40472222

Longitude: 27.51528

Nearest town: Paltamo

Distance from neaerst town: 16 km

Relevant Research Questions

One important goal of research is to produce applicable research information on regulated rivers to develop their fisheries and to promote sustainable use of their migratory fish populations. The main themes of this subject of ongoing studies at Kainuu Fisheries Research Station are:

a) Methods to restorate the natural reproduction of endangered salmonid species,

b) The Effects of River restoration and watershed land use on fish populations,

c) Effects of stream restoration on fish populations, benthic invertebrates and stream functions and

d) Energetic consequences of hydropeaking conditions on salmon fry.

Research is performed to promote the conservation, diversity and management of Finnish fish species, many of them classified threatened. Especially many salmon and brown trout populations are endangered and dependent on restocking. However, restocking of fish has not been successful in many cases. The main reason for this is the high mortality of the released fish. One obvious reason is that life skills that are important for survival in the wild are weakened by domestication selection and unnatural rearing environment. To counteract this we are developing more natural rearing methods, release methods and the methods decreasing the rate of domestication. One of the recent subjects of ongoing experiments is ‘Evolutionary restoration of fish populations impacted by human-induced selection’. Fishing-induced evolution occurs, when fishing imposes a non-zero selection differential on a heritable trait. It may occur in life-historical, physiological, morphological and behavioral traits both due to direct and correlated selection. Research is testing if different methods could be used to decrease the possible unwanted fishing-induced selection on fish populations.


Kainuu Fisheries Research station has unique experimental facilities for aquatic ecological, environmental or management-related research in laboratory and in semi natural experimental arenas. No other comparable facility is yet available in the European Union.


In many of the experimental facilities at the station especially including many of the semi-natural streams there already is versatile monitoring PIT-tag (Passive integrated transponder) and underwater camera systems available for experimental studies. PIT-tag systems at the station have been developed to serve as a tool for monitoring behavior of fish in different experimental arenas. Also user-friendly filtering programs are available for all the users at the station (www.pitdata.net). Recently most of the researchers working at the station have used these monitoring systems in their studies and the need to extend these devices to cover more of the devices is increasing.

Experimental Capabilities

Experimental Facilities

Several different facilities with good number of replicates are available at the station, see details http://www.kfrs.fi/en/station/ and http://www.kfrs.fi/binary/file/-/id/3/fid/142/ and one 7 hectares lake (70 km from the station) that can be drained.

Experiments duration: Weeks, Months, Years;

Experimental Aerea

Total area: 70000 m²

See details in www.kfrs.fi

Available area: 10000 m²

See details of the diffferent facilities: http://www.kfrs.fi/en/station/ and http://www.kfrs.fi/binary/file/-/id/3/fid/142/

Experimental Unit Size

unit size: 50 m²

Many different sized units, for example area of one experimental stream pool system is 50 m2 and height is 200 cm. See details: http://www.kfrs.fi/en/station/ see details http://www.kfrs.fi/binary/file/-/id/3/fid/142/


Replicates number: 500

Cross-Ecosystem Manipulation

The impact of various land uses on aquatic ecosystems

Manipulation Techniques

Temporary storage

  • Drying oven
  • Freezer
  • Liquid N
  • Other

Available Instruments

  • ultrasonic flow meter, flow rate meter
  • pit tracking devices
  • underwater cameras
  • basic field and laboratory instruments
  • electric fishing devices

Electricity available on site.

Distance from Laboratory facilities


Years measured: 29


Mean Temperature: 1.5 °C

February Mean Temperature: -17 °C

July Mean Temperature: 15 °C


Mean Annual Speed: 6.2 m/s

Max. Annual Speed: m/s

Dominant Direction:


Precipitation type: Rain, Snow;

Total annual precipitation: 600 mm

Mean snow cover duration: days

State Variables

Continuously Measured

  • (aquatic) Oxygen content
  • (aquatic) Water temperature

Spot Measured

  • (aquatic) Chlorophyl
  • (aquatic) Current speed
  • (aquatic) Nutrient levels
  • (aquatic) pH
  • Air temperature
  • Population densities

Environmental Pressures

Variable Ecosystem Status
Warming River Active
Precip River Active
Hydro River Active
Watereutroph River Active
Soilerosion River Active
Habitatfrag River Active
Pests River Active
Biodiversity River Active
Warming Lake Active
Precip Lake Active
Hydro Lake Active
UV Lake Planned
Watereutroph Lake Active
Soilerosion Lake Active
Habitatfrag Lake Active
Pests Lake Active
Biodiversity Lake Active

On site Staff and Accomodation

Peak season staff

Up to 14 people

Off season staff

Up to 8 people

Visiting personnel

Up to 14 visitors

Bedrooms available

Up to 14 beds

Showers on site

Showers on site

Laundry on site

Laundry on site