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Nature Index values stable in freshwater


1.1 Norwegian ecosystems will achieve good status and deliver ecosystem services.


Ecological status and trends for the following major ecosystems: marine and coastal waters, rivers and lakes, wetlands, forest, mountains and cultural landscapes (see the Norwegian Nature Index and the Water Management Regulations)

Nature Index values for freshwater


Are we moving in the right direction? Published by the Norwegian Environment Agency

This indicator for rivers and lakes describes the state of biodiversity in freshwater ecosystems as measured by the Norwegian Nature Index in 2014. An indicator based on the requirements of the Water Management Regulations is described here.

For Norway as a whole, the state of biodiversity in freshwater ecosystems has been stable since 1990. This is confirmed by results from 2014, which show an overall Nature Index value of 0.75 for freshwater ecosystems (in this system, the reference state is given the value 1, and is defined to correspond to minimal disturbance from human activities.) Nature Index figures are somewhat lower for Southern Norway and parts of Western Norway. This is explained by the widespread and persistent acidification of river systems caused by long-range transport of pollutants.

More locally, there are parts of Eastern and Central Norway where the state of biodiversity is somewhat poorer, mainly as a result of agricultural pollution and subsequent eutrophication problems and large-scale regulation of rivers for hydropower production. Even in North and Western Norway, where Nature Index figures are highest, large-scale hydropower regulation has had a negative impact on biodiversity in some areas.

Locally, inputs of nutrients, primarily from agriculture, can be a problem in all regions of the country, particularly in lowland areas.

The overall stability of Nature Index figures in freshwater is partly explained by a range of management measures that Norway has introduced. They include protection for some threatened species, steps to reduce inputs of acidifying substances and liming of river systems. However, at the same time other trends have had negative impacts on biodiversity. These include increasing eutrophication and habitat degradation caused by physical alterations, for example in connection with infrastructure development.