Institute of Fish Resources, BG – 9000 Varna, Bulgaria
Dineva, S., 2013. Black Sea water environment along the Bulgarian coast. Bulg. J. Agric. Sci., Supplement 1: 6–11
Recent performed hydrological and hydrochemical survey along the Bulgarian Black Sea coast has aimed to update the knowledge for principal characteristics of the water environment under climate change impact. Study of the waters along the Bulgarian Black Sea coast at 1 mile in front of Cape Kaliakra, Balchik, Albena, Cape Galata, Cape Ilandzik, Kamchia River outfall, Dvoinitsa River outfall, Cape Emine, and Nesebar was carried out in 2011. Research of Varna Bay at net of stations and of Burgas Bay at Koketrice Bank was performed. In order to investigate the influence of Beloslav Lake and Varna Lake on the Varna Bay, the Lake system was studied, as well. In-situ measurements of temperature, salinity, dissolved oxygen, and oxygen saturation were done. Some of the expected main climate change outcomes for the Mediterranean, including the Black Sea region, during the 21st century were ascertained along the Bulgarian Black Sea coast. Climate change impact on the thermo-haline structure of the Bulgarian Black Sea was found. The year’s maximum sea temperature both of surface and bottom coastal waters in August 2011 was above the long-term mean, and sea temperature was with anomaly in excess of 0.87°C in the surface waters and 2.97°C in the bottom waters. Increase in salinity with 0.96 psu in the coastal waters over 2011 in comparison with 1990s was found. Salinity was above the long-term average with 2.22 psu in June. Varna Bay’s salinity during 2011 was above the long-term average with 0.46 psu in the surface waters and 0.80 psu in the bottom waters. Considerable deviations of the ecosystems from the equilibrium state in both the Varna Bay and Beloslav–Varna Lake system were established. The obtained results throughout the performed survey are of key importance as to the Black Sea ecosystem function assessment along the Bulgarian coast. This research is essential for safeguarding the future security, health, well-being of human societies, marine and fish industry development, and installation of the necessary infrastructure related to appropriate facilities, as well.