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Baltic Sea

70 % of Helsinki Area consists of sea. Seawater quality is monitored regularly at several observation stations.

The Helsinki sea inlets and costal areas are no longer as eutrophic as earlier. This is the result of more effective wastewater treatment, the closing down of small wastewater plants following the completion of the Viikinmäki main wastewater treatment plant, and the conducting of wastewater, from 1987 onwards, beyond the archipelago, about 7 km from the shore.

As a result of earlier wastewater loading, the bays are still eutrophic, as the nutrients deposited in the bottom sediment are still being released because of the decreased oxygen content in the water. In order to improve the critical state of the Gulf of Finland and of the entire Baltic Sea, Finland is, for example, an active participant in the purification of St. Petersburg´s wastewaters.

06.12.2019 18:40

Sea water temperature and amount of algae

The water quality and the state of the sea area is monitored biweekly through water samples and various measurements

Monitoring of Long Term Trends

The water quality of the Helsinki coastal area has changed markedly during the last 40 years.