A natural coastal lake to the west of Varna, the largest Bulgarian sea-port. The northern shore is fringed by reedbeds of Phragmites, Typha and Schoenoplectus, while other parts are steeply sloping. There are sand-banks, as well as small saltpans in the westernmostpart of the complex, whose banks are overgrown with Salicornia. The lake was converted in the 1970s into a ship-canal connecting the Black Sea and Lake Beloslav, and there are many industrial installations (factories, ports, etc.), roads and railways along the lake-shore.
The complex is important for breeding Recurvirostra avosetta, which nest at the saltpans. It is the only wetland between Shabla and Durankulak lakes in the north and the Burgas lakes to the south, and thus is an important staging and wintering area for waterbirds, especially Pelecanus crispus and Phalacrocorax pygmeus. It is also a major migratory bottleneck site, where up to 50,000 Ciconia ciconia pass overhead each autumn. Species of global conservation concern that do not meet IBA criteria: Aythya nyroca (min. 9 on passage), Oxyura leucocephala (max. 3 in winter).
Pressure/threats to key biodiversity
Problems include water pollution by industry and the overexploitation of fish stocks.
National Low International None125 ha of IBA covered by Protected Landscape (Kazashko, 125 ha).