Various indicators are used for monitoring water quality in the Baltic Sea.

The water quality of the Baltic Sea is regularly monitored from many different perspectives. Several government research institutes take part in the monitoring. Results on water quality are based on samples from the open sea and coastal waters, as well as satellite imaging.

Find out more about the water quality indicators – and their seasonal variation and long-term trends – on each indicator’s page. The indicators used for measuring water quality are temperature, salinity, oxygen conditions, amount of algae, water transparency, turpidity, nitrogen concentration and phosphorus concentration.

 Observation stations are spread all over finnish coastal areas
Water quality is investigated from water samples taken from monitoring stations. In addition to samples, remote sensing is used as an aid, which produces observations from more extensive areas.