The Oder Estuary - IOW

2
m³), Zarow (90 Mio m³), and Ryck (60 Mio m³) into the western Oder Estuary come to 1.1 km³
water. That is only 60 % of the water volume of the river Oder which flows away through the
western Estuary.
The main point sources of discharge into the German part of the Oder Estuary are the sewage
plants of the cities of Greifswald (70.000 Population Equivalents), Anklam (40.000 PE), and
Wolgast (25.000 PE). In addition there are several other small discharging municipalities.
From six measuring points in the German part of the Szczecin Lagoon, four stations in the
Peenestrom and four stations in the southern part of the Greifswalder Bodden samples were taken
to measure the parameters of the water quality. Locations of the main sources (river and point
source) and the measurement grid of the western Oder Estuary are shown in Figure 1.
Figure 1 The measurement grid of the western Oder Estuary
2 Organic matter load
The organic matter load is measured as Biological Oxygen Demand after five days (BOD5). The
major part of BOD5 load entered the western Oder Estuary via the river Peene (Tab. 1). The
riverine influx of organic matter depends on the runoff. The highest amount of it was determined in
the year with the highest runoff which was in 1994. The runoffs of the rivers Peene, Uecker,
Zarow, and Ryck were similar in 1991 and 1997 but the BOD5 load decreased.