The Danube Delta (Romanian: Delta Dunarii; Russian: ?????? ?????, Delt'a Dunaya; Ukrainian: ?????? ?????, Del'ta Dunaju) is the second largest delta
in Europe, after the Volga Delta, and the best preserved on the continent . The greater part of the Danube Delta lies in Romania (Tulcea county),
while its northern part, on the left bank of the Chilia arm, is situated in Ukraine (Odessa Oblast). The approximate surface is 4152 km˛, of which
3446 km˛ are in Romania. If the lagoons of Razim-Sinoe (1015 km˛ of which 863km˛ water surface; situated in the south, but attached to the Danube
Delta from geological and ecological perspecives, as well as being the combined territory of the World Heritage Site) are to be added, the
considered area of the Danube Delta grows to 5165 km˛.
The Danube Delta began forming around 11,000 B.C. in a gulf of the Black Sea, when the sea level was 50 to 60 m lower than today. An offshore bar blocked the gulf into a lagoon, which subsequently led to its filling with sediments. The Danube Delta is a low alluvial plain, mostly covered by wetlands and water. It consists of an intricate pattern of marshes, channels, streamlets and lakes. The average altitude is 0.52 m, with 20% of the territory below sea level, and more than half not exceeding one meter in altitude. Just the pre-delatic, continental remnants (88.5 km˛) stand higher (Letea levee 12.4 m, Caraorman 7 m); minimum altitude is -3m. The largest lakes are Dranov (21.7 km˛), Rosu (14.5 km˛), Gorgova (13.8 km˛), etc.
Arms of the Danube:
The Danube branches into three main arms into the delta, Chilia, Sulina, and Sfântu Gheorghe. The first two branches form the Tulcea arm, which continues as a single body for several kilometers after the separation with Chilia arm. At the mouths of each arm alluvionary processes take place, sign that the delta is continuing its expansion.
Main Arms of the Danube
Length (km) Flow (mł\s)
Chilia 120 3800
Sulina 64 1250
Sfântu Gheorghe 70 1500
Chilia, in the north, the longest, youngest, and most vigorous, with two secondary internal deltas and one in full process of formation at its mouth.
Sulina, the central and thus the shortest arm, which consequently led to its extensive use for traffic and severe transformation. At its mouth is located the main port and the single settlement with urban charactersitics of the Romanian part of the delta. Because of the alluvium deposited at its mouth, a channel gradually advancing into the sea (presently it has 10 km), was built in order to protect the navigation.
Sfântu Gheorghe (Saint George in Romanian), in the south, is the oldest and more sparsely populated. Its alluvium has led to the creation, beginning with 1897, of the Sacalin islands, which as of today measure 19 km in length.
The climate of the Danube Delta is continental with strong influences from the vicinity of the Black Sea and its prevalent amphibian environment. It is the driest and sunniest region (70 days with blue sky, 2500 hours of sunshine/year) of Romania. The mean annual temperature is 11°C (-1°C in January and 22°C in July), with mean precipitation between 400and 300 mm/year, decreasing from west to east. The evaporation is around 1000 mm/year, favorized and amplified by the strong and frequent winds, resulting in long periods of drought in the summer. The northwest winds cause frequent storms in spring and autumn. In the interior of the delta the continental character of the climate is very pronounced.
The Danube Delta falls within east European steppe ecosystem, with Mediterranean influences. As a young region in full process of consolidation, the Danube Delta represents a very favourable place for the development of highly diverse flora and fauna, unique in Europe, with numerous rare species. It hosts 23 natural ecosystems, but due to the extent of wetlands the aquatic environment is prevalent; the terrestrial environment is also present on the higher grounds of the continental levees, where xerophile ecosystems have developed. Between the aquatic and terrestrial environments, is interposed a swampy, easily flooded strip of original flora and fauna, with means of adaptation for water or land, depending on the season or the hydrological regime. At the contact between freshwater and sea water, some special physical, chemical and biological processes take place, which determined biologists to consider this area as a very different ecosystem called beforedelta. Musura Gulf, north of Sulina, and Sfântu Gheorghe Gulf are considered the most representative for this type of ecosystem.
Situated on major migratory routes, and providing adequate conditions for nesting and hatching, the Danube Delta is a magnet for birds from six major eco-regions of the world, including the Mongolian, Arctic and Siberian. There are over 320 species of birds found in the delta during summer, of which 166 are hatching species and 159 are migratory. Over one million individuals (swans, wild ducks, bald coots, etc.) winter here.
Ecosystems of Running Water comprises tha Danubes arms, as well as a series of more important streamlets and channels. It is an environment very rich in plankton, worms, mollusca, ephemerides, grubs, spongiae, with numerous species of fish, such as the carp, pike perch, sheat fish, and freshwater sturgeons (sterlet, Vyza, Danube mackerel).
Ecosystem of Stagnant Water includes the lakes, to which various ponds, streamlets and channels are added. They are characterized by a rich floating and submerse flora (Myriophyllum, Ceratophyllum, Vallisneria etc. under the water; Nymphaea Alba, Nuphar luteum, Trapa natans, Alisma plantago etc., floating plants with roots near the lakes borders; Salvinia natans, Stratiotes aloides, Spirogyra etc., floating plants without roots, having negative effects for the aquatic bioproductivity). Of the fish, the most important are Tinca tinca, Abramis brama, Scardinius erytrophalmus, Carassius auratus gibelio, Silurus glanis, Perca fluviatilis, Exos lucius etc.
Ecosystems of Marshy and Flooding Areas: The reed plats and floating reed islands (called plaur in Romania are the most common and well known components of the Danube Delta. Vegetation of this ecosystem consists of common reed (Phragmites communis), and near river banks mace reed (Typha latifolia, Typha angustifolia), sedge (Carex dioica, Carex stricta), Dutch rush (Scirpus radicans, Scirpus lacustris), brook mint (Menta aquatica) etc. They constitute ideal spawning and nestling grounds. The plaur is a mixture of reed roots, grass and soil, usually floating or anchored on the bottom. As a rule, the reed surrounds the lakes and ponds, slowly invading the water surface. This type of ecosystem is noted for the variety and large populations of birds, some of them very rare. The most important are the tufted duck (Aythya fuligula, red crested pochard (Netta rufina), mallard (Anas platyrhincos), Greylag goose (Anser anser), Pygmy cormorant (Phalacrocorax pygmaeus), purple heron (Ardea purpurea), Great white egret (Egretta alba), little egret (Egretta garzetta), Spoon bill (Platalea leucorodia), White pelican (Pelecanus onocrotalus), Dalmatian pelican (Pelecanus crispus), Mute swan (Cygnus olor), Glossy ibis (Plegadis falcinellus). A recent and welcomed spreading has the pheasant (Phasianus colchicus). Among the mammals, there is the otter (Lutra lutra), mink (Mustela lutreola), little ermine (Mustela erminea aestiva), wild boar (Sus scrofa), wild cat (Felis silvestris), and in the winter, the hare (Lepus europaeus), and on the brink of disappearing from the delta, the wolf and the fox. The enot dog (Nyctereutes procynoides), bizam (Onda zibethica), and to some extent nutria (Myocastor coypus) are recent species successfully adapted.
The firm land of the delta used to be covered with large groves of willow trees, cut almost entirely and replaced with Canadian poplars. On the riverbanks kept in natural state, small groves of willow trees (Salix alba, Salix fragilis, Salix purpurea, Salix petandra, Salix triandra etc.) can still be found, mixed with white poplar (Populus alba). Occasionally, the willow trees form corridors along the Danubes arms and bigger channels. On the levees of Letea and Caraorman, mixed forests of oaks (Quercus robur, Quercus pedunculiflora) with various trees (Fraxinus pallisae, Ulmus foliacea, Populus tremula), shrubs (Prunus spinosa, Crataegus monogyna, Rosa canina, Berberis vulgaris etc.), and liana (Vitis silvestris, Hedera helix, Humulus lupulus, Periploca graeca, which reaches up to 25m) grow on sand dunes. On the Letea levee, these exotic looking forests grow especially in the depressions between the sand dunes, in small groves called hasmace. Fauna of this region includes Meadow Viper (Vipera ursinii), Osprey (Pandion haliaetus), Eagle Owl (Bubo bubo), etc.
The Danube Delta is perhaps the least inhabited region of temperate Europe. In the Romanian side live about 15,000 people, of which 4,600 in the port of Sulina, which gives an average density of approx. 2 inhabitants per km˛. The rest is scattered in 27 villages, of which only three, all situated marginally, have more than 500 people (2002). The town of Tulcea, at the western edge of the delta, but not included in it, has a population of 92,000 (2002). It represents the node of the region and the gate to the delta. The acute isolation and the harsh conditions of living, based mainly on subsistence, made the Danube Delta a place of emigration, or at least of transit. Very few of the people born here stay through adulthood; at the same time, the origins of the inhabitants fall within a wide range, as people from the most various places of Romania can be found in the delta. The total population has somewhat remained constant throughout the 20th century; there were 12,000 inhabitants in the 1890s, and 14,000 before the Second World War. Romanians count for approximately 80%, and Ukrainians for 10%. Other people living in the delta include Greeks, Turks and Bulgarians (1992). Distinctive for the region, but very vague as an ethnic entity are the Lipovans, descendants of the Orthodox Old Rite followers who fled Russia in the 18th century from religious persecution. About a third of the employed population is engaged in fishing and pisciculture, while another third is engaged in farming (1996). However, the quasi-totality practice fishing, more or less legally, as a means of subsistence or extra money.
The Ukrainian part of the delta is very well populated compared to the Romanian one. The town of Izmail has a population of 85,000, and Vilkovo, the main center of Lipovan community, 11,000 (2001).