Assessment Criteria for Eutrophication Areas

The German Bight is characterised by mean residence times of 33 days in the inner Bight and of 67 days in the larger German Bight area. The shallow Bight (mostly < 40 m depth) receives large amounts of nutrients from the rivers Elbe, Weser and Ems, from transboundary transports along with the coastal current and from the atmosphere. Nutrient river loads, reached annual means of 280 % for TN and of 450 % for TP of the natural background concentrations in the period 1990 – 1997 . The main discharge occurs during winter / spring, mostly leaving the area before the growing season starts. Especially phosphate discharges were reduced significantly since the early 1990s, causing phosphate decreases in the total German Bight and  within all salinity regimes during winter.