THE IMPACT OF TEMPERATURE ON THE WATER QUALITY OF THE BALTIC SEA

Abstract

The article examines the impact of water temperature on the quality indicators of the Baltic Sea, including nitrogen and phosphorus compounds as well as biochemical oxygen demand (BOD₇). The relevance of the study is determined by climate change-induced warming of the Baltic Sea, which accelerates eutrophication processes and threatens ecosystem stability. The results revealed that rising water temperature significantly increased total nitrogen and phosphorus concentrations and intensified BOD₇ fluctuations, with 20 °C identified as the critical threshold for the most intensive chemical changes. These processes create favourable conditions for cyanobacterial blooms, accelerate eutrophication, and deteriorate the ecological status of the sea. The findings highlight that climate-driven water temperature rise is one of the key factors affecting the quality of Baltic Sea ecosystems.