The Oder Estuary - IOW

30
µmol/l
µmol/l
µmol/l
70
60
50
40
30
20
10
0
70
60
50
40
30
20
10
0
70
60
50
40
30
20
10
0
Jahresgang NH4-N im Kleinen Haff
Jahre 1990 - 1999
J F M A M J J A S O N D
Jahresgang NH4-N im Großen Haff
Jahre 1990 - 1999
J F M A M J J A S O N D
Jahresgang NH4-N in der Pommerschen Bucht
Jahre 1990 - 1999
J F M A M J J A S O N D
95%
5%
75%
25%
Median
95%
5%
75%
25%
Median
95%
5%
75%
25%
Median
µmol/l
µmol/l
µmol/l
70
60
50
40
30
20
10
0
70
60
50
40
30
20
10
0
70
60
50
40
30
20
10
0
Jahresgang NH4-N im Kleinen Haff
Jahre 1980 - 1989
J F M A M J J A S O N D
Jahresgang NH4-N im Großen Haff
Jahre 1980 - 1989
J F M A M J J A S O N D
Jahresgang NH4-N in der Pommerschen Bucht
Jahre 1980 - 1989
J F M A M J J A S O N D
Figure 5.7: Annual course of ammonium (µmol/l) in the Kleines Haff (top), the Wielki Zalew
(middle) and the Pomeranian Bay (bottom). The figures refer to the periods 1980 –
1989 (right) and 1990 – 1999 (left). Data source: State Agency of Environment,
Protection of Nature and Geology Mecklenburg-Vorpommern (LUNG) and West
Pomeranian Voivodeship Inspectorate in Szczecin (WIOS).
Source for ammonium are the mineralization of organic matter and the input with the Oder river.
The moving average concentrations between 1980 and 2000 does not show a significant tend (Fig.
5.6). More detailed comparisons of the median ammonium concentrations between single month of
the 1980’s and the 1990’s suggest, that a small reduction of the concentrations took place in all
three systems (Fig. 5.8). Due to the high variabilty of the data this reduction remains uncertain.
95%
5%
75%
25%
Median
95%
5%
75%
25%
Median
95%
5%
75%
25%
Median