Danube river

Second largest river in Europe

The river Danube originates in the Black Forest in Germany. With a length of 2,780 km it is the second largest river in Germany. Its catchment area covers 800,000 km2 which makes the Danube river basin the second largest in Central Europe. The Danube is the most important waterway linking Central to South-eastern Europe.

The sampling area covers the German section of the Danube on a length of 586 km and includes its catchment area of approximately 56,000 km2, which is the third largest in Germany.

Other important features of the Danube are:

  • The Danube is a so-called cold-water river strongly influenced by its alpine tributaries. The large water masses of these tributaries result in an average discharge of the Danube which is twice as big as that of the river Elbe.
  • To enable intensive shipping, the hydromorphology of the river was strongly modified, e.g. by numerous barrages and straightening of long river sections. Compared to the 19th century, the area of the flood plains has been reduced by 80% and only about half of the river is still in a near-natural state.
  • The Danube is an important source of drinking water for about 10 million people.
  • Five riparian states of the Danube obtain significant portions of their energy from hydroelectric power plants on the Danube, namely Germany, Austria, the Slovak Republic, the Republic of Serbia, and Romania.
  • The Danube is the only river system in Germany that drains into the Black Sea instead of the North or Baltic Sea.
  • Compared to other German rivers the Danube differs in its fauna due to the immigration of many Pontic-Caspian species.
  • This may result in different competitive conditions and food sources for bream and zebra mussels in the Danube compared to the sampling areas in the Rhine and Elbe.


Oberhalb Illermündung Only sub-area in headwaters
Unterhalb Altmühlmündung The central section of the river Danube in Germany
Unterhalb Innmündung Last sub-area of the river Danube before leaving Germany


Zebra mussel Common mussel species as invasive animal in rivers and lakes with high information level for water pollution
Bream Bioindicator in rivers and lakes
Suspended particulate matter Fine insoluble mineral or organic particles in the water phase


Metals Eighty percent of all elements on earth are metals
Nonmetals Only eighteen elements in the periodic table
Organometallic compounds Organic substances with at least one metall atom
Chlorohydrocarbons Group of organic compounds with at least one covalently bonded chlorine atom
DDT and metabolites Toxic and persistent organochloropesticide
Hexachlorocyclohexane Several isomeric compounds among the group of chlorinated hydrocarbons
Polycyclic Aromatic Hydrocarbons Group of organic compounds with at least three condensed six-membered rings
Biocides and plant protection products Chemical agents against harmful organisms and for plant protection
Per- and polyfluoroalkyl compounds Organic compounds which are fully (per-) or partially (poly-) fluorinated
Stable Isotopes Atoms of one element with different weights
Flame Retardants Flame retardants reduce the flammability of objects
Supplementary parameters Additional information for the interpretation of contamination data

Sampling period

2002 - 2019