Ditch drainage in the catchment areas has increased the leaching of sand into downstream. Log and boulder structures are installed in order to remove sand from the streams. The aim of adding natural wood, with branches, is to diversify the habitats of brown trout, for instance. The picture shows a stream in the headwaters of River Isojoki in Ostrobothnia. Photo: Metsähallitus / Pauliina Louhi.

The habitat restorations aim at improving the habitats of waterfowl, freshwater pearl mussels, fish and other organisms. In addition to these objectives, restoration measures may promote the recreational use of the area and contribute to enhancing the amenity or values related to the conservation of nature and the landscape.

Most running waters in Finland are dammed and cleared for the purposes of drainage, flood control and power generation. This has reduced the diversity of aquatic habitats. The project involves enhancing the diversity of habitats in running waters by rolling boulders and spawning gravel into waterways. Natural wood and aquatic moss, which are not commonly used for restoration purposes in Finland, are also being inserted. Running water restoration measures are being carried out in all of our target areas.

Eutrophication and the end of cattle grazing have led to the overgrowing of many of the country’s waterfowl habitats. We will restore these habitats by raising the water level, removing excessive riparian vegetation, removing small predators and enhancing grazing. These measures have been shown to diversify the numbers of waders in particular, while enhancing the abundance of other bird species in waterways.

In some lakes covered by the project, the fish community has become distorted due to excessive numbers of small roaches, breams and perch. We carry out management fishing in these lakes to remove the excessive nutrients accumulated in the water bodies and to increase the percentage of predatory fish, such as pikeperch or large perch among the fish fauna. At a later stage, higher numbers of predatory fish will naturally control the roach fish populations in the lakes.

Last updated 22 May 2020