142
W. Schramm
0.8
0.6
0.2
OL-~~~~~~~~~~~~~~~~~~~~~~~~~~~ __
1958 1960
1965
1970
1975
1980
1985
1990
6
N03-N
0
0
'/,
a
<00 '{i' ~ Jl-l--II--"? 4
Jan-Apr
0
0
i
I§ 0
i 00 ) , : .... ~ t
a
",1:06''''' '"
W
~~_---o 0 0
'f,'
- '"
E
",
75
[ 2
8.25
8.00
~
~J.~~O -:
0 8
~
-----~ ~ 10 f
o
g
Salinity
Jan - Apr
a
~ 7.75
0
w
~ ____ ~-~--o-~--o---~~
o
00
7.50
II 0
1965
1970
1975
1980
1985
1990
Fig. 5.5. Trends of nutrient concentration and salinity under winter conditions in the
surface layer of the southeastern Gothland Sea from 1958-1990. (After Nehring 1991)
More comprehensive long-term studies of coastal eutrophication in
the Baltic were undertaken in the waters of the Island of Funen county in
the Belt Sea of Denmark (Funen County Council 1991). Over the 14-year
study period form 1976-1990, no clear long-term trends in the winter
levels of inorganic P and N were observed. During this period, nitratenitrogen values varied considerably, following closely the pattern of land
run-off, which was to a great extent controlled by precipitation. Inorganic phosphorus concentrations, on the other hand, could not directly
be related to land run-off. However, they followed the pattern of the