Indicator: Bottom substrate

Soft bottom with infaunal organism such as polychaetae. Photo: Peter Leopold, Norwegian Polar Institute

Bottom substrate
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Rationale: State of the bottom substrate defines he quality of the benthic community life as well as the levels of pollutants such as heavy metals, oil etc. which are important in the planning of environmental research and security measures to ensure the safety of oil rigs.


Topic: Abiotic

Component: Bottom substrate

Type of indicator: E, state of the ecosystem.

Priority of indicator: e, essential.

Reference level:

Environmental quality objective:

Action limit:


• Grain size (gravel, sand, silt and mud) (Rosgeo/Sevmorgeo, MMBI, MAGE)
• Boulder bed (Rosgeo/Sevmorgeo, MAGE)
• Organic matter (Rosgeo/Sevmorgeo, Okeangeologiya)
• Colour of bottom sediment (Rosgeo/Sevmorgeo)

Responsible institution



Map of ecosystems vulnerable to the chemical content of the near-bottom water and sediments. Source: Rosgeo/Sevmorgeo