Europe’s second longest river after the Volga, the Danube arises at the confluence of its headwaters, the Brigach and Breg Rivers, near the town of Donaueschingen in the Black Forest region of Germany. The river flows for a distance of around 2,857 kilometers, passing through 10 European countries along the way, and draining an area of 817,000 square kilometers, before finally draining into the Black Sea via the Danube Delta, which is shared between Romania and Ukraine. Romania shares 29% of the Danube’s river basin. Hungary, Serbia, and Austria each share approximately 10% of the river’s basin, while Germany, Bulgaria, Croatia, Slovakia, the Ukraine, and Moldova each share less than 10% of the Danube’s watershed.
The Danube River has always played a prominent role in shaping the history of ancient Europe. Evidences of certain early human cultures, including the Danubian Neolithic culture and the Vučedol culture, have been found in the river basin. Greek sailors exploited the river as early as the 7th Century BCE for trade purposes, while the Roman Empire used the river to define parts of the frontier boundaries of its kingdom. Fortresses and castles were built by the Romans on the river, and Roman fleets would patrol the river in efforts to defend the empire from its many tribal enemies living on the other side. The Ottoman Empire also used the Danube for defensive purposes in the later centuries to come. However, in the early 19th Century, the Queen of Hungary and Bohemia, Maria Theresa, recognized the potential of the Danube as a trade route, and thus started operating riverboats carrying cargo upon the river. In the following years, several treaties were signed and conventions were held to determine and discuss the sharing of the Danube’s waters. As a result of years and years of such negotiations, currently only those countries bordering the river are allowed exclusive rights to access the water resources of the Danube.
Today, the Danube River is like a lifeline for much of Europe, providing drinking water to over 20 million people and housing more than 83 million people in its watershed. The ten countries sharing the waters of the Danube use the river for navigation, hydroelectric power generation, fishing, and the irrigation of farmlands alike. Water needed for industrial and domestic uses are also extracted from this river. Izmayil in Ukraine, Ruse in Bulgaria, Budapest in Hungary, and Vienna in Austria are some of the important port cities based along the river. A number of navigation channels have been constructed along the river, including the Danube–Black Sea Canal and the Main–Danube Canal, facilitating the transport of people and goods along and across the river. The Ðerdap (Djerdap) High Dam and the Iron Gate power station, situated between Serbia and Romania, is the largest hydroelectric power-generating project on the Danube. The Danube River Basin is also riddled with significant tourist spots. As a result, leisure cruises are commonplace on the river, and the presence of globally famous cities and cultures, as well as an abundance of natural wealth, draw millions of tourists into the countries sharing the river basin.
Habitat and Biodiversity
The extensive Danube River Basin supports a wide variety of natural habitats, like the Black Forest of Germany, the Alpine ecosystem of Austria, the puszta plains of Hungary, the wetlands of the Danube Delta, and the Danube islands of Bulgaria. More than 100 fish species, including 5 species of sturgeon, inhabit the waters of the Danube River. The river basin also supports a large variety of avian fauna, including such rare bird species as the Black stork, White pelican, and White-tailed eagle. The Danube River basin is also a part of the Worldwide Fund for Wildlife's “Global 200” list of ecoregions.
Environmental Threats and Territorial Disputes
The Danube River, like most major rivers of the world, has been overfished and overpolluted. The lethal combination of pollutant release into the Danube’s waters, illegal and irresponsible fishing, and extensive damming of the river’s waters has resulted in a severe decline in the water quality of the Danube. There are 28 dams on the Danube, ranging from its source to the mouth of the river delta, which block the natural flow of its waters and disrupt the natural order of sediment transfer from upstream to downstream, consequently facilitating heavy erosion in the river delta as well. These dams also act as a barrier to the natural migration of fish species of the river. Today, the level of damage to the river is so high that several kinds of sturgeon, fish species whose eggs are famous for caviar and have survived for 200 million years on Earth, are presently "endangered" in the region.