Surface waters

Finland is uniquely rich in surface waters, with a grand total of 187,888 lakes and ponds larger than 500 square metres, and rivers totalling 25,000 kilometres in length. Almost a tenth of the country‘s total land area is covered by water. The total length of the intricate coastlines of the Baltic Sea in the west and the south add up to an impressive 46,000 kilometres when the shorelines of islands are included.

Although there is plenty of water visible on the surface, most of these waters are not very deep.  Finland’s many thousands of large and small lakes contain a total of only 235 cubic kilometres of water – the same amount of water that flows through the Amazon in just two weeks. All of Finland’s lakes together amount to less then a third of the volume of Russia’s Lake Ladoga. Finland’s lakes and coastal waters are so shallow because the rocks in this geologically stable region of Europe have been gradually evened out by erosion over millions of years, and during successive recent ice ages.

Shallow waters vulnerable to pollution

Finland’s shallow lakes are easily contaminated by pollution. Even relatively low concentrations of excess nutrients, acidic deposition or other harmful contaminants can easily disrupt their sensitive aquatic ecosystems.

Harmful pollutants also eventually run down through lakes and rivers into the sea. Finland lies almost entirely within the catchment area of the Baltic Sea, although rivers and streams in northernmost Finnish Lapland and parts of north-eastern Finland flow into the Barents Sea and the White Sea.

The Baltic Sea is also shallow, and sensitive to pollution. The Baltic is virtually an inland sea, and is burdened by exceptionally heavy loads of contaminants originating from its extensive catchment area, which is home to more than 80 million people.

Pollutant loads declining – but not quickly enough

Discharges of harmful substances into Finland’s inland and coastal waters have fallen considerably since the “bad old days” a few decades ago. But there is still plenty of room for improvement in the state of many lakes, and particularly in the Baltic Sea, where nutrient pollution from diffuse sources such as farmland continues to cause eutrophication and harmful algal blooms.

Finland sees international co-operation on the protection of the Baltic marine environment as vital, especially since most of the pollution entering the Baltic originates from other countries. Rapidly increasing shipping in the Baltic represents a serious environmental risk, especially where the transportation of large quantities of oil and other harmful chemicals is concerned.

Finland is an active member of the Helsinki Commission, the intergovernmental organisation responsible for co-ordinating the protection of the Baltic marine environment.