Monitoring seasonal water physicochemical conditions in Cedronas urban lake (Vilnius, Lithuania)

Abstract

Urban lakes supply many ecosystem services and are very much appreciated for recreational activities. For this, water quality is a key aspect. In this work, we monitored water physical-chemical variables, including temperature, pH, electrical conductivity (EC), total dissolved solids (TDS), nitrogen (N), phosphorus (P), and potassium (K) concentrations in an urban lake located in Vilnius in Summer and Autumn. Per season, 20 samples were collected. The results showed that temperature, pH, EC, N, P and K were significantly higher in Summer than in Autumn, while the opposite was identified in TDS. pH and temperature were negatively associated with TDS, and pH, EC, N, P and K were negatively associated with the previous elements. Data variability was higher in the Summer than in the Autumn. Overall, the highest concentrations of nutrients combined with high temperatures can promote water eutrophication and reduce the lake's capacity for recreation.