Structure: State of surface waters, stream fragmentation

ECOLOGICAL STATE OF THE BALTIC SEA COASTAL AREAS

The ecological state of more than half (54%) of the Baltic Sea coastal areas in Finland have been assessed as moderate in quality in 2013.  None of the coastal areas were in a high quality state, 25% of them were assessed as good in quality, 20% as poor and 1% as bad.

ECOLOGICAL STATE OF INLAND WATERS

In 2013 the ecological state was evaluated as excellent or good in 85% of the lake area. There have been no significant changes in water quality or microalgae production caused by nutrient loading. The state of 13% of lake area was classified as moderate and 1% as poor or bad. Lakes in these categories are located next to extensive farmlands or below industrial or urban areas and are often small or medium sized. Most commonly these lakes have been affected by nutrient run-offs from agricultural land especially in south-western Finland where arable lands are mainly erosion sensitive clay soils. Additionally, the old sediments rich in nutrients from past decades still affect water quality at present.

Most of the rivers evaluated as in excellent or good ecological state (altogether 64%) flow in the northern Finland. In these rivers migrant fish species can reproduce naturally and also sensitive fish and benthos species occur. Most rivers evaluated moderate (23%), poor (9%) or bad (2%) are located in the western and south-western Finland. These rivers are affected by eutrophication caused mainly by agriculture. The discharge of rivers with weaker quality is also often being regulated both because of hydropower production and flood protection.

Between 2008–2013 a higher proportion of lakes were classified as declining rather than improving in quality. More than 3% of the lake area was deteriorating and 2% was improving. On the contrary, most changes in river quality were positive. About 2% of the river length was improving in quality as 0.6% was declining.                                                                       

State of the surface waters. Environmental Administration.