How is the status of waters monitored?

Lumpeenlehti piirtyy veden alta sinistä taivasta vasten.

Finnish lakes, rivers and coastal waters have been monitored for decades. The results of this monitoring show us how the status of aquatic environments has developed over the years.

Monitoring the status of waters is a massive undertaking, as there are thousands of observation points, and water samples may be collected several times a year. The samples are checked for such properties as the colour and oxygen content of the water as well as the concentrations of nutrients, meaning nitrogen and phosphorus. Water temperature and transparency are also measured.

The biocenoses of observation points are also studied every few years, including planktonic algae, benthic animals, fish, aquatic plants as well as periphyton attached to rock surfaces.

Such parties as water protection associations, industrial plants, municipalities and the central government’s environmental administration take part in the monitoring. Industries and municipalities have a duty to monitor the impact of their wastewater emissions on lakes and rivers.

All monitoring results are compiled into a single register, regardless of who produced them. This register, which can be openly accessed by not only the authorities but all citizens, shows that the ecological status of Finnish waters has improved over the last 50 years.

While the scale of the monitoring is large, it does not cover every single one of the hundreds of thousands of lakes, rivers and other waters in Finland. The data can be complemented with model calculations, but models do not make up for actual monitoring of waters.