Many of the problems coupled to large local discharges of contaminants
to the Gulf of Bothnia are now decreasing, although the concentration
s of pollutants in sediments and biota will remain high for a long tim
e. The long-term development of the pollution situation in the Gulf of
Bothnia will essentially be governed by conditions outside the area.
Many contaminants are widely spread and may accumulate far from the so
urces, Therefore, differences in vulnerability will be crucial far whe
re environmental effects occur, The ecosystems of the Gulf of Bothnia
are particularly vulnerable because of almost oligotrophic conditions
and a climate that may favor accumulation of persistent organic pollut
ants.