site.btaKalimok-Brashlen Protected Site: Happy 21st Anniversary!

Kalimok-Brashlen Protected Site: Happy 21st Anniversary!
Kalimok-Brashlen Protected Site: Happy 21st Anniversary!
BTA Photo

On July 9, 2001, a ministerial order gave protected status to the Kalimok-Brashlen area. The purpose was to conserve the diversity of the unique wetland ecosystems and landscapes typical of the region, as well as the habitats of valuable plant and animal species.

With its total area of 5,772 ha, Kalimok–Brushlen is the biggest protected site in Bulgaria. It is located along the former flooded lowland between Babovo and Tutrakan, Northeastern Bulgaria, and includes all Bulgarian islands in this part of the Danube: Mishka, Malak Brashlen, Pyasachnik, Bezimenen, Kalimok and Radetski. The protected site lies within the territory of the municipalities of Slivo Pole and Tutrakan. 

The prevailing opinion about protected areas is that they only apply restrictions on certain human activities, such as building, industrial and agriculture production.

Kalimok–Brushlen is an illustration of how much more a protected status entails.

“Returning to naturalness” in Kalimok-Brushlen included a large-scale restoration project, which started in 2002 and ended in 2008. In order to achieve efficient restoration of the wetlands it was necessary to allow the Danube to flow again into what was once marshes. For that purpose, engineering facilities were built, including sluices, channels, dykes to protect the adjacent land, as well as access roads. Thus opportunities were provided for controlled flooding. The first flooding was successfully carried out in April 2008. 

The protection of wetlands had to overcome a period of negative public attitudes towards the very existence of such landscapes. Natural wetlands - now considered among the most biologically diverse of all ecosystems, one of the Earth’s most precious treasures, serving as a home to a wide range of plant and animal species - were seen by older generations as useless or dangerous places. The long list of names (swamps, bogs, moors, marches, mires and similar words) in both English and Bulgarian shows distinct acid taste. Wetlands were – and sometimes still are – seen as an antonym of “arable lands”. And as the main culprit for the spread of malaria. In the interwar period, for instance, serious funds were used for draining the marshes in the Black Sea region and along the course of big rivers. The Bulgarian Refugee Loan (1925), guaranteed by the League of Nations, provided funds for such activities, seen as means for combating malaria transmission. In Petrich region alone, more than 52 km of drainage canals were built, for draining some 1,600 ha of wetlands.

At that time, the Kalimok and Brushlen marshes were entirely flooded as were the floodplains nearby the Danube river. The wetlands - permanent marshes and areas with regular flooding - were covering about 3,500 ha. When the draining of the Danube marshes began in 1952, direct connection with the Danube was severed and a flood protection system of dikes and drainage canals was built. (Construction of these started as early as 1945.) As a result, major parts of the floodplains were converted to arable lands, and part of the marshes remained as wetlands without an open connection with the Danube river. (This has had significant impact on fish stocks, not only in the floodplains, but also in the Danube. Because of absent or limited suitable breeding locations, fish populations have been declining.)

Construction of some 520 ha of fishponds in the Tutrakan Marsh region started in 1981. They required a lot of electricity for their operation. The high level of ground water during the spring required the artificial control of water levels in the fishbreeding water bodies. During the dry period in summer and autumn it was necessary to refill the ponds with water using pumps. Fish breeding in the fishponds ceased in 1993 because of financial problems.

Since 2001 the landscape of the site has been gradually changing. This visual effect is caused primarily by the flora. The flooded forests have their unique look - mainly due to the strong stems of the Virginia creeper (Parthenocissus), to some lianas species, such as the silk vine (Periploca graeca), and also to algae and mosses.

Along with the natural flooded forest of willows and poplars, large spaces are covered with Bulrush (Typha latifolia), reed (Phragmites australis), indigo bush (Amorpha fruticosa) as well as some rare and endangered plant species as summer snowflake (Leucojum aestivum), yellow flag (Iris pseudacorus), water chestnut (Trapa natans), yellow water lily (Nuphar lutea) and floating watermoss (Salvinia natans).

The flooded forests and the marshes on the PS are very important for the feeding and breeding of the birds in the area. About 242 bird species are found in the area of which more than 134 are nesting there. PS Kalimok-Brashlen is home to many rare bird species, such as the Great Cormorant (Phalacrocorax carbo) and the Pigmy cormorant (Phalacrocorax pygmeus), the Common Spoonbill (Platalea leucorodia), the Ferruginous Duck (Aythya nyroca), the Squacco Heron (Ardeola ralloides), the Whiskered Tern (Chlidonias hybridus). The loud, grating “krek-krek” call of the male Corn crake (Crex crex) can be heard 1.5 km away.

Over 20 species of reptiles and amphibians could be found on the territory of the protected area, as well as 59 fish species. Some of them, as their names in Latin suggest, are endemic for the Danube River: the Biban (Acerina cernua danubica) and Bulgarian golden loach, Shtipok, (Sabanejewia bulgarica).

Since the malaria issue was touched as an image-forming factor of wetlands, it is worth mentioning the balance of nature to be witnessed here. Ecological systems are usually in a stable equilibrium and it is well seen in the role of a small, unimpressive in size (4-5 cm) and appearance fish called Varlovka or Belitsa (Leucaspius delineatus). This species lives in shallow waters and feeds on mosquitos larvae. The Varlovka is characterized by great appetite, very fast reproductivity and large number of progeny. It is, in short, the ideal anti-mosquito weapon. It is also much more effective and safer than chemicals used in both ground-level and aerial spraying (Chemicals destroy all kind of insects, while Varlovka’s prime target are mosquito larvae.)

[Common mammals on the territory of the protected site are the European Ground Squirrel (Spermophilus citellus), known as Souslik, which is a globally endangered species. Other common mammals in Kalimok-Brashlen are the Wild Boar (Sus scrofa), the Red Deer (Cervus elaphus), the Roe Deer (Capreolus capreolus). The Red Fox (Vulpes vulpes), the Common Jackal (Canis aureus), the Wildcat (Felis silvestris), the European Water Vole (Arvicola amphibius) and the Harvest Mouse (Micromys minutus) are also found on the territory. Rarely could be found the European Otter (Lutra lutra).]

The ecosystem balance of Kalimok-Brashlen PS is still fragile, slowly recovering from decades of high anthropogenic pressure: drainage of the marshes, building of dikes and fishponds, overgrazing, deforestation. The ecosystem suffers from other results of human activity: At the end of March, the media reported four wildfires in just one week on the territory of Kalimok-Brashlen.


In order to improve the existing birds’ habitats on the territory of Kalimok-Brashlen and also to create preconditions to attract new rare and endangered bird species, the project "Improving Birds' Habitats in Protected Site Kalimok-Brashlen" was implemented. The project was implemented under a bigger project - NATUREGIO Floodplains managed by Alfred Toepfer Academy for Nature Conservation in cooperation with the WWF Danube Carpathian Programme and with the financial support of several German donor foundations. The main project activity was the construction of an Artificial Nesting Platforms on the territory of Kalimok marsh. 




By 18:56 on 01.12.2023 Today`s news

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