The Oder Estuary - IOW

µmol/l
µmol/l
400
350
300
250
200
150
100
50
0
400
350
300
250
200
150
100
50
0
Jahresgang Nt im Kleinen Haff
Jahre 1991 - 1999
J F M A M J J A S O N D
Jahresgang Nt im Großen Haff
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
µmol/l
µmol/l
400
350
300
250
200
150
100
50
0
400
350
300
250
200
150
100
50
0
Jahresgang Nt in der Pommerschen Bucht
Jahre 1991 - 1999
J F M A M J J A S O N D
Jahresgang Nt im Großen Haff
Jahre 1983 - 1989
J F M A M J J A S O N D
Figure 5.12: Annual course of total nitrogen concentrations (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).
20
10
0
-10
-20
-30
-40
A M J J A S O N
Figure 5.13: Changes of total nitrogen concentrations (µmol/l) in the Wielki Zalew (large lagoon)
between 1980–1989 and 1990–1999 (left). Data source: West Pomeranian
Voivodeship Inspectorate in Szczecin (WIOS).
Total nitrogen (Nt) covers the inorganic nitrogen compounds, nitrate, nitrite and ammonium, as
well as organic fractions. As a rough average estimation one can say that nitrate contributes about
35
95%
5%
75%
25%
Median
95%
5%
75%
25%
Median