Large lakes in good condition; problems in rivers and coastal waters
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Photo: Pirjo Ferin-Westerholm
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Finnish Environment Institute (SYKE) & the Ministry of the Environment
Most of Finland’s surface waters – lakes, rivers and coastal waters – are classified as having an excellent or good ecological status. Almost a third of the assessed lakes are in a state poorer than ”good”, as are about half of the country’s rivers, and just over half of the total area of Finland’s coastal waters. Classification of the chemical status of Finland’s water bodies is still in progress, but preliminary findings suggest that concentrations of hazardous and harmful substances are generally so low that their chemical status is good.
The data used in classifying the status of Finland’s water bodies has been compiled by the country’s 13 regional environment centres, with data on fish contributed by the Finnish Game and Fisheries Research Institute. Almost all of the country’s coastal waters and major inland waters used as waterways have been classified. Smaller rivers and lakes have generally not been classified due to their large number and the lack of sufficient data.
Regional variations in the status of rivers
Northern Finland’s rivers are generally in an excellent or good ecological state. Rivers whose status is classified as being only moderate or poor are more numerous in coastal regions of Southern, Western, and Southwestern Finland. In such rivers aquatic ecosystems are affected by various factors including high nutrient loads from farmland, hydrological engineering, and in some cases high concentrations of metals and acidity, caused by artificial drainage, especially in areas with acid-sulphate soils.
Smaller lakes worst affected
A third of Finland’s larger lakes show no significant changes in their ecological status. Eutrophication and the consequences of water level regulation, such as the spread of reed beds or increased erosion, reduce the overall status of many lakes from excellent to good, although the state of their open waters may still be excellent. Examples include the major lakes of Päijänne, Näsijärvi, Oulujärvi and Inarinjärvi. Larger lakes that have long been affected by runoff from farmland or wastewater discharges, such as Lappajärvi and Vanajavesi, are generally classified as having a “moderate” ecological status.
Almost a third of Finland’s small or medium-sized lakes are in a state poorer than good. Such lakes are often affected by algal blooms and other problems associated with eutrophication, especially in agricultural regions.
Coastal waters faring better in the north
The ecological status of marine waters in the Gulf of Bothnia is generally good, although some inshore waters are only classified as moderate.
Inshore waters further south in the Gulf of Finland and the Archipelago Sea generally have a poor ecological status, although conditions further out in the archipelagoes tend to be moderate. In the Eastern Gulf of Finland the situation is the reverse, with conditions poorer in the outer archipelago, where benthic animals have almost vanished in wide areas affected by oxygen depletion. The worst affected coastal waters are around the archipelagoes of Tammisaari and Inkoo in the Gulf of Finland west of Helsinki.
New classification criteria
The EU Water Framework Directive and related new Finnish legislation have led to changes in the classification of the ecological statuses of water bodies, which are now assessed from the perspective of entire aquatic ecosystems. Assessments of the chemical statuses of water bodies compare the concentrations of hazardous and harmful substances to specific environmental norms defined for 53 substances and groups of substances.
A target has been set that waters in Finland and throughout the EU should have a good ecological status by 2015, and that the statuses of waters already classified as excellent or good should not worsen. A good ecological status means for instance that the impacts of human activities on fish, benthic animals, aquatic plants and planktonic algae must be minor or negligible. The statuses of artificial or greatly changed water bodies (including reservoirs) should be good in relation to their best achievable status. Assessments of the impacts of human activities are based on the conditions needed to maintain the undisturbed life cycles and reproduction of ecological communities in entire river basins.
Classifications to be applied in river basin management plans
Finland’s regional environment centres are currently drawing up official river basin management plans, which will be available for everyone to comment on the related proposals over a six-month period from the end of September 2008. These plans contain measures designed to achieve or preserve a good or excellent ecological status for all water bodies. The newly completed classification of the statuses of Finland’s surface waters forms a vital basis for the planning of such measures.
Ecological status of surface waters by numbers of water bodies
in each category
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Source: Regional Environment Centres and Finnish Environment Institute
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Ecological status of surface waters by proportion of total length (rivers) or surface area
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By proportion of total length (rivers) or surface area.
Source: Regional Environment Centres and Finnish Environment Institute
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Map of the ecological and chemical status of surface waters
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Source: Regional Environment Centres and Finnish Environment Institute
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For more information:
Kari-Matti Vuori, research professor, Finnish Environment Institute (SYKE): tel. +358 40 543 2227
Jukka Matinvesi, environment counselor, Ministry of the Environment:
tel. +358 400 143 911
Classification of coastal waters:
Saara Bäck, senior adviser, Ministry of the Environment: tel. +358 400 285 410
Impacts on fish:
Jukka Ruuhijärvi, researcher, Finnish Game and Fisheries Research Institute (RKTL): Tel. +358 400 219 613
Communications officials:
Ulla Sonck, Finnish Environment Institute (SYKE): tel. +358 040 740 2186
Ulla Ahonen, Ministry of the Environment: tel. +358 50 524 5269
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