13 
(average 3%) of those on soft bottoms. Thus, the 
lower value given in our inventory estimates may 
be more realistic, but since the inventory is still 
based on a limited number of observations, and 
taking into account the considerable variability of 
the data, it is more relevant to give a range rather 
than a single value as a result. 
The spatial distribution of the total amounts of Cs- 
137 at different sampling stations in the Baltic Sea 
is shown in Figure 2. The highest total amounts 
of Cs-137 per m 2 were observed in the Bothnian 
Sea. The maximum value, 125 000 Bq nr 2 , was 
recorded in 1998 from the northernmost part of 
the Bothnian Sea (llus et al., 2003), and values 
exceeding 110 000 Bq nr 2 were also recorded in 
the sea area off Gavle. The median total amount 
of Cs-137 was 36 400 Bq nr 2 on the soft bottoms 
of the Bothnian Sea. The corresponding value for 
the soft sediments in the Bothnian Bay was 9 700 
Bq nr 2 . 
In the Gulf of Finland, the maximum amount 
of Cs-137 was 42 700 Bq nr 2 in the middle of 
the eastern part in 2003, and values exceeding 
38 000 Bq nr 2 were also recorded in the eastern 
most parts of the Gulf. The median total amount 
in the soft sediments of the Gulf of Finland was 
10 400 Bq nr 2 . In the Gulf of Riga, the maximum 
total amount of Cs-137 was 21 800 Bq nr 2 at a 
h 
£ 
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Total amounts of Cs-137 (Bq/m2) 
» 
100 
000 
to 
150 
000 
50 
000 
to 
100 
000 
20 
000 
to 
50 
000 
10 
000 
to 
20 
000 
0 
to 
10 
000 
Figure 2. 
Total amounts of 
Cs-137 (Bq nr 2 ) at 
different sampling sta 
tions in the Baltic Sea 
at the beginning of the 
2000s. 
Long-lived radionuclides in the seabed of the Baltic Sea