Excessive nutrient load has upset the underwater summer season

The summer is a period of growth under the surface as well. The sunlight penetrating the water provides plants with the energy that they need to photosynthesise, grow and reproduce. However, in recent times this growth has become excessive. The phenomenon, known as eutrophication, is caused by the excessive nutrient loading of aquatic habitats. Eutrophication leads to increased water turbidity, changes in species ratios and oxygen loss in the water layers near the bottom. In practice, the process is visible in the form of mats of filamentous algae covering rocks, the increasing prevalence of cyprinids, the mass deaths of bottom-dwelling fauna and the mass occurrence of blue-green algae, which hinders the recreational use of shores.

Grey seals can be spotted in the waters of Ruissalo as well
Baltic herring is an important link in the Baltic Sea food chain