The Danube Delta Treasure

Director of Grigore Antipa National Museum of Natural History in Bucharest

The Danube Delta has a diverse fauna and flora which, in the context of the global preoccupation for environmental preservation, are major points of interest for Europe and even for the whole planet. The Danube Delta remains the place in which many species that are protected by law are "at home". The climate, the soil, the hydrographic and topographic conditions allowed the development of a diversity of ecosystems with interrelations that we generally overlook at first sight. Through photosynthesis, plants are primary producers; many vegetarian creatures feed on them; ecologists call the latter primary consumers; these primary consumers constitute the food for other consumers of a superior degree but in order for an ecosystem to function correctly, it needs decomposers. What would the Danube do with the whole biomass produced there, without the saprophyte fungi (that feed on dead plants and animals), and without the decomposing bacteria? Who hasn't heard about the abundance of algae of the Black Sea after tons of dead fish were brought to the shore by the waves? The biocenoses would be suffocated in the Delta but for the decomposers. But what is a delta? A part of a watercourse, on the outfall in an ocean, sea, lake or another watercourse; that is why deltas are marine, lacustrine, made by rivers or by rain. Deltas are also called dejection cones, and they are usually in the shape of the letter Δ-the fourth Greek letter. When specialists state that "the earth is alive", they refer precisely to the circuit of the matter and energy in complex ecosystems. In the Danube Delta, the latter are exemplified by the presence of the coppices covered by poplars and willows, of the wide surfaces of reed, of the sand banks and dunes with oak and ash forests and several species of lianas. The presence of streams, backwaters and lakes was the reason why in 1990 the Danube Delta was considered a moist area of international importance (Convention Ramsar-Iran, 1971) and biosphere reserve (Law 82/1993). In its capacity of a moist area it includes pools and swamps, natural and artificial lakes, and in its capacity of biosphere reserve it has characteristic ecosystems and areas which are strictly protected, some others of traditional usage of the natural resources (fish, game with fur and feathers, reed, bulrush, osier) and buffer areas, for the decrease of the anthropological impact. Both statuses entail, among other things, international collaborations (as a logistical support) for the research, monitoring and maintenance of the moist areas and the sustainable usage of the natural resources, to the benefit of the local communities, without the alteration of the natural state of the ecosystems. How did the Danube Delta appear? Two million years ago the Danube flowed into the sea at the level of the town of Oltenita today. Back then, the region was inhabited by mammoths, reindeer, elks, and wooly rhinoceros whose fossils were discovered in the sedimentary soils. During the first glacial periods (Gunz, Mindel and Riss), when the level of the Black Sea decreased, the course of the Danube moved to the north, and during the last ice age (Wurm-115,000-25,000 ago), when the level of the Black Sea decreased even more, the Danube received the rivers of Dniester, Bug and Dnieper in its bed. After Wurm or in the post-glacial period, at the same time as the rise in temperature which determined the melting of the ice, the materials brought by the water settled one over the other. That is why the age of the Danube Delta is estimated to be only about 8000-10,000 years, for the river delta; to the east of the line Chilia-Histria, the dry land was formed in the last 300-400 years. The maritime sand banks of Letea, Caraorman, Sfantu Gheorghe are genuine islands of the river-maritime delta, while the area between Ceatal Chitila (the first bifurcation of the Danube) and the above mentioned sand banks represent the river delta. Today the Danube Delta, with a surface of about 430,000 ha on the Romanian territory, extends between the three branches and the lagoon complex Razim-Sinoe; another 100,000 ha of the Danube Delta are on Ukrainian territory. The Chilia branch is 116 km long and carries 58% of the total flow of the Danube to the sea, of 6350 m3/sec, at the entrance in the delta. The Sulina branch is the shortest (only 63 km, after the works undertaken to level off and deepen the bed) and carries to the sea 19% of the water of the Danube; the rest of 23% flows along the 96 km of the Sfantu Gheorghe branch – which is the most southern and the most picturesque.There are many natural links between the three branches: lakes, channels and marshes (ghioluri) among which artificial canals were dug in order to refresh the water in the dead branches and the pools with stagnant water, for the increase of fish production. The first canal, dug in 1907, was given the name of the Romanian sovereign Carol I. The great lake Razim forms a unitary system with the lakes of Golovita, Zmeica and Sinoe, with depths of 2 or 3 m, on a surface of 87,000 ha. The Danube Delta is positioned between Cape Midia (44°20'40'') and Chilia Branch (45°27'00'') at km 43 latitude North and between Cotul Pisicii ("Cat's Bend", 28°10'50'') and Sulina (longitude 28°42'45'' East). The parallel of latitude 45°00'00'' North is equidistant from both the Equator and the North Pole and crosses the Danube Delta between the towns of Sfantu Gheorghe and Sulina. As the 45° parallel crosses the Danube Delta, we are amazed by the fact that this paradise of birds is situated exactly equidistant from the North Pole and the Equator, as well as halfway between the Atlantic Ocean and the Urals. The crossroads between the various climatic, floral, faunal influences, which are arctic, alpine, western and central-European, Pannonian, Balkan, sub-Mediterranean and even Caucasian and Turanian-Iranian led to a diversification of plants (more than 1600 species) and animals (more than 3500 species). With a surface of about 6000 km2 the Danube Delta represents a complex of ecosystems, out of which specialists were able to identify a number of thirty, all with optimal standards of living for plants and animals.The Danube Delta is situated on the route of the migratory birds. More than 325 species of birds, represented through populations that, when flying, can darken the sky, find there good conditions of shelter and rest, food and nesting. An important part of the species of fish of the European continent (some of great economic value) live in the Danube Delta as well.It is a unique place, with numerous species and big populations of butterflies, dragonflies, bugs and crickets, frogs and creeping animals, birds and mammals (raccoon-dogs, otters, muskrats, boars, rabbits, deer). One can indeed say that the Danube Delta is a true Noah's Ark, a haven of birds that come from all over the world. From Asia come bald eagles, summer swans and big cormorants. From the south, from the African continent, come numerous species of small birds, out of which the white pelican and the Dalmatian pelican are the most impressive. From the Artic region at winter time come the red-neck goose, the white-fronted goose, the lesser white-fronted goose, the dunlin etc.Many species are protected by the law: the shelduck, the ruddy shelduck, the white-tailed eagle that nests in the forest of Letea, the great white egret, the spoonbill, the black-throated diver, the black-winged stilt, the curlew, the roller, and the already mentioned pelicans. The Danube Delta is the place to catch the most precious species of fish: pike and pike perch, carp, sheatfish, rapacious carp and crucian carp, perch and tench, bream and eels. Among the ninety species of fish there are also the famous sturgeons which produce caviar. What is important in the Delta? With the total surface mentioned above, the Danube Delta is ranked 22nd in the world and third in Europe. It has the largest surface with compact reed thickets in the world. It is the only delta in the world which is declared a biosphere reserve. Due to its numerous identified ecosystems, it has a complex biodiversity and a genetic pool of a priceless value of the natural patrimony. The hydrological regime, with the fluctuations in the level of the water, determines the migration of some species of vertebrates and non-vertebrates; fishermen know that when the water level rises they cannot catch any fish precisely due to the fact that the latter are disturbed by it.Almost half of the surface of the Danube Delta is temporarily under water (especially in spring time), 45% permanently covered with water, and only 5% (the big sandbanks – grinduri, mentioned above) represent the genuine dry land, which is never flooded. Most specialists acknowledge the pelican and the water lily as the emblems of the Danube Delta. Nevertheless, some consider that in fact reed is more representative of the place, since 250,000 ha are covered in this plant. Reed is four or five meters high, and it forms thickets impossible to penetrate; rhizomes curl in the mud and form a thick, tangled layer in which the rest of the plants grow roots. This root carpet is most often fragmented and raised to the surface, thus forming the "plaur" (a floating reed islet), a word which in Slavic means precisely to float. In its 1.5 meter thickness a layer rich in humus is formed, which allows the development of a rich vegetation. The water fern is very common, especially there where the islet is thicker. On the other hand, the places in which Myosotis grows (the beautiful blue flower of forget-me not) must not be stepped on, because the islet is thin and there is no way back from under it. The villagers walk on the paths made by the boars, which avoid the dangerous spots. Besides plants, the islet shelters several species of birds and mammals. That is why their sure escape is the thin islet.The Danube Delta is a miraculous, out of the ordinary place, a place of all forms of life. It is in fact a mixture of all hypostases of life, in which the predominant state can't be but that of the whole deltaic complex. Wherever it seems that there is total harmony, everything is in fact a fight to put up with the competition. In the water, on land (whose surface is very small and most of it is often flooded), in the air – the creatures watch for one another, live the anxiety of the waiting, they exercise their senses, defense and attack reflexes. All of them are in turn preys and attackers. Singing birds fear birds of prey; insects fear the fish, frogs, snakes and birds; fish fear predatory fish and ichthyophagous birds; rats fear foxes, badgers, weasels, ermines, as well as day and night birds of prey. We therefore understand that in this place everything is linked to everything; from this point of view, the Danube Delta is a complex ecosystem, with numerous types of habitats (coppices covered in willows and poplars, large surfaces of reed, backwaters, streams and lakes) with an impressive variety of aquatic plants and animals. Sand dunes, with forests of pedunculate oak and water ash trees or the lianas of subtropical climate form large sand banks covered in forests, which alternate with open and dry lands-genuine sand steppes. Against the background of the luxuriant vegetation in most parts of the Danube Delta, one of the most impressive shows of colors and lights take place. The colors of the 1600 species of plants, trees and shrubs (according to the botanists' inventories) overwhelm the visitor who adventured into the heart of the delta. Besides the already mentioned forests, one runs very frequently into mint, which has delicate essential oils, as well as numerous melliferous plants, and the aquatic vegetation is ennobled by delicate white and yellow water lilies. And then again, how many hues can we see while watching the sunset or the sunrise, over the water of a channel? Most often the lands of the delta are animated by the flight of birds. Pelicans and swans, egrets and cormorants, wild geese and ducks, divers and moor hens, warblers, pendulines and crests skim over the water pools, the reed or the meadows on the sand banks. The world of insects is dominant and the slow flight of butterflies, as well as the swift flight of the dragonflies, please the eye of the visitor. The 3500 species of vertebrates and invertebrates listed in the zoologists' inventories don't do any harm and avoid human beings. Only the mosquitoes aggress the tourists who have left the repellents at home. But the smoke of a reed fire or some willow twigs will successfully replace any other measure.The lagoon complex Razelm-Sinoe – the ex-marine gulf (around 880 km2) together with more islands and sand banks in the south of Sf. Gheorghe branch belong to the Danube Delta as well. The more important is island of Popina, with an altitude of 48 m (!) – a very high one, considering the fact that at Bechet the Danube is at only 28 m above the sea level. The Wolves Sandbank (Grindul Lupilor) is 17 km long and only 1 km wide. This complex calls to our mind its ancient name, Halmyris, on the shore of which the colonists of Miletus built the fortress of Histria seven centuries before Christ, as a harbor to the Black Sea. The few ruins uncovered by the archeologists are suggestive of the active life of the fortress, which had a public bath, churches, warehouse for weapons against the Asian invasions, etc. The ruins of another fortress (Arganum), built by the merchants of Miletus as well, were discovered near Cape Dolojman. Both fortresses bear witness to the mud depositories which in time silted the old gulf, the shores of which bear the traces of the material Neolithic culture and of Christianity.
Nowadays, the human population still inhabiting the delta represents a variety of ethnic minorities, either refugees or merely people who settled down there for the sake of the peaceful environment and its rich resources. Orthodox Russians or Lipovans, and Ukrainians or Haholi, ran away from religious persecutions. From inside Romania came inhabitants of all the historical provinces who accepted to live away from crowded cities and adapted to the new conditions, with picturesque landscapes and with the feeling of liberty, but with the permanent worry about all the bare necessities.

by Dumitru Murariu