Seawater Physico-chemical Parameters in Varna Bay (Bulgaria)

Seawater is one of the most important natural resources, vital for ecosystems and for our priorities around food, climate change, recreation of the world’s citizens, as well as for the well-being of human societies. The global pressures on seawater and the related sectors call for research, followed by actions of the integrated water resources management in order to be shaped positive change on today’s most pressing issues, water being a substantial one. Considering major global and regional water-related concerns, study about distribution of seawater physico-chemical parameters in Varna Bay was done in 2019. Analysis, visualization of the data, and creating of maps were made by XLSTAT and Ocean Data View software. The ascertained values of temperature and salinity in Varna Bay and the corresponding ones in the nearby area of the connected Varna Lake were slightly different. The maximum concentrations of nitrite nitrogen, nitrate nitrogen, and phosphate phosphorus were found in the south area of Varna Bay. Lake water was approximately twice more enriched with organic matter compared to bay water. The distribution of temperature and salinity in Varna Bay and in the nearby area of Varna Lake has indicated that the lake mainly contained seawater. The distribution of nutrients has displayed the passing lake water through the south bay area as an anthropogenic factor. Lake lead pollution has influenced the organic matter in Varna Bay. The ascertained distribution of essential seawater physico-chemical parameters and the discussed issues are of key significance for the integrated water resources management, as well as provide knowledge about the marine environment in this Black Sea area.