The Oder Estuary - IOW

44
µmol/l
µmol/l
20
18
16
14
12
10
8
6
4
2
0
20
18
16
14
12
10
8
6
4
2
0
Jahresgang Pt im Kleinen Haff
Jahre 1992 - 1999
J F M A M J J A S O N D
Jahresgang Pt im Großen Haff
Jahre 1992 - 1999
J F M A M J J A S O N D
95%
5%
75%
25%
Median
95%
5%
75%
25%
Median
Jahresgang Pt in der Pommerschen Bucht
Jahre 1992 - 1999
Figure 6.7: Annual course of total phosphorus concentrations (µmol/l) in the Kleines Haff (top,
left), the Pomeranian Bay (top, right) and the Wielki Zalew (bottom, left) and the
(bottom) for the period 1992 – 1999. The figure at the bottom, right displays the data
for the Wielki Zalew between 1980-1991. Data source: State Agency of
Environment, Protection of Nature and Geology Mecklenburg-Vorpommern
(LUNG) and West Pomeranian Voivodeship Inspectorate in Szczecin (WIOS).
The total phosphorus (Pt) consists, as a rough average estimation, to about 50 % of phosphate and
to 50 % of organic compounds. In similarity to nitrogen, the ratio between inorganic and organic
compounds depend on the season.
The data shows a long-term Pt-reduction of nearly 40 % in the lagoon. With about 50 %, this is
reduction is even more pronounced in the Pomeranian Bay. The annual dynamics of Pt is similar to
phosphorus, but weaker. During May, when inorganic phosphorus is largely depleted in the water
column, organic compounds have the highest portion in Pt.
µmol/l
µmol/l
6
5
4
3
2
1
0
20
18
16
14
12
10
8
6
4
2
0
J F M A M J J A S O N D
Jahresgang Pt im Großen Haff
Jahre 1983 - 1991
J F M A M J J A S O N D
95%
5%
75%
25%
Median
95%
5%
75%
25%
Median