The protected area “Kalimok – Brashlen” extends in the Tutrakan valley and includes all the islands in Bulgaria, which are located in this part of the river Danube: Mishka, Malak Brashlen, Golyam Brashlen, Pyasachnik, Bezimenen, Kalimok and Radetzky. In the recent past, Brashlen and Tutrakan swamps were located in Tutrakan floodplain. These were the largest swamps near the Danube, with an area of approximately 19 sq.km. The floodplain represents the swamp lakes and river mouths permanently flooded. By the late 40’s of last century, the great marshlands were known for the large populations of fishes and the jobs related to catching fish – knitting fishing nets and boat building. After 1952 the marshes were drained to get new farmland, and between them and the Danube dams were built. So one of the largest wetlands in Bulgaria, known for its incredible biological diversity, ceases to exist. In the 80s of last century on the small plots of land which were permanently flooded by high groundwater, and were unsuitable for farming, hatcheries have been built to function as such until the mid-90s. During the period of 2003-2008, with support from the Global Environment Fund canals are dug and hatches are built thus restoring the connection between the Danube and the former ponds and the land around them. The dams of the ponds are destroyed to allow water to flow over the entire bay. So in 2009 the Danube for the first time is infused with fresh water and fish population from the former marshes, thus new life is brought into one of the largest wetlands in Bulgaria – “Kalimok – Brashlen”. The total surface of the protected areas is 75 502 hectares, and the most important part of it is water surface area of 5952 acres, the land of the village of Nova Cherna, Municipality Tutrakan.
For visitors Kalimok – Brashlen is appreciated because it offers the possibility to pass through dams and ponds and to observe wildlife. Such close monitoring is impossible for large protected areas where monitoring is done from a distance.
Since 1989, close to the protected area functions a biological and experimental facility – “Kalimok” near the Institute of Zoology of the Academy of Sciences – Bulgaria for artificially raising the rare and endangered birds – ruddy Shel duck (Tadorna ferruginea), which is known for the fact that, under natural conditions it nests in holes of foxes and badgers and its youngsters and the mammals’ coexist.
Fishing is prohibited throughout the year, in the territory of the former ponds and islands from the protected area.
Plant diversity is expressed by more than 370 plants, including rare and protected ones as white water lily, Burduche, South mehurka, Key, Damn nut, Shtitolistni kakichki, flying Lake, singleton horseradish, Tselolisten clematis. At international level the protected area is one of the most important one in terms of water birds along the Danube River. On the territory of the former ponds have been counted 188 bird species, out of which 61 are included in the Red Book of Bulgaria (1985). Among the species encountered, 85 are of European conservation concern. The ponds are of global importance for Ferruginous duck / Aythya nyroca and a resting place for Dalmatian pelican / Pelecanus crispu. Here it lives one of two breeding colonies of black-winged stilt, common stilt, or pied stilt / Himantopus himantopus. During the breeding season “Kalimok – Brashlen” is one of the most important places in the European Union for the ferruginous duck, Nycticorax Nycticorax, Egretta garzetta Ardeola ralloides, Botaurus stellaris, Platalea leucorodia, Himantopus himantopus, Coracias garrulus and three species of terns – Sterna Hirundo, Chlidonias hybridus and Chlidonias niger. During the migration period in the region gathers a significant number of Ciconia ciconia and Plegadis falcinellus. During this period and in winter fisheries are of majour importance for Phalacrocorax pygmeus and Anser anser. They are an important place for spending the winter for Turdus pilaris. In winter a large number of water birds gather around the fisheries such as Branta ruficollis, Anser albifrons and others.
Mishka island is one of the largest breeding colonies for cormorants, spoonbills, grey heron, little egret and night heron. Radetski island country is the only natural habitat of cypress. The island is located west of Tutrakan, close to the town.