BOD5 concentrations in rivers between 1992 and 2008 in different sea regions of Europe

Concentrations are expressed as the average of annual mean concentrations. Up to 3-year gaps of missing values have been interpolated or extrapolated. Only complete series with no missing values after this interpolation/extrapolation are included. Number of river monitoring stations included in analysis per region and country within the corresponding region is noted in brackets. BOD7 data (Estonia, Finland, Lithuania (1996-2008), Latvia (1996-2001)) has been recalculated into BOD5 data

Atlantic Ocean (258): Spain (116), France (121), United Kingdom (15), Ireland (6);

Baltic Sea (168): Czech Republic (11), Denmark (12), Estonia (53), Finland (23), Lithuania (28), Latvia (39), Slovakia (2);

Black Sea (358): Austria (134), Bulgaria (39), Czech Republic (20), Hungary (98), Slovenia (16), Slovakia (51);

Mediterranean Sea (271): Albania (9), Bulgaria (46), Spain (111), France (90), FYR of Macedonia (9), Slovenia (6);

North Sea (211): Austria (11), Belgium (26), Czech Republic (39), Denmark (23), France (95), United Kingdom (14), Luxembourg (3).

BOD5:

Standard method for indirect measurement of the amount of organic pollution (that can be oxidized biologically) in a sample of water. BOD test procedure is based on the activities of bacteria and other aerobic microorganisms (microbes), which feed on organic matter in presence of oxygen. The result of a BOD test indicates the amount of water-dissolved oxygen (expressed as parts per million or milligrams per liter of water) consumed by microbes incubated in darkness for five days at an ambient temperature of 20°C. Higher the BOD, higher the amount of pollution in the test sample. For the contaminants that cannot be oxidized biologically, chemical oxygen demand (COD) method is used. Also called BOD5.