5 The Baltic Sea and Its Transition Zones
W. SCHRAMM
5.1 Introduction
The Baltic Sea and its transition zones probably range among the most
encumbered marine waters around the world.
Bordered by nine countries, most of them densely populated and
highly industrialized, and not far away from the centres of air pollution
in Europe, this brackish inland sea is particularly endangered and susceptible to man made eutrophication and pollution due to its specific
hydrographical conditions and geomorphological features. During the
past two decades, an increasing number of observations have been made,
which indicate the response of the ecosystem Baltic to these man-made
impacts.
The international concern of the Baltic states about the alarming signs
and symptoms of pollution and eutrophication led to the Helsinki Convention on the protection of the Baltic environment (Baltic Marine Environment Protection Commission, HELCOM) in 1974.
Since the beginning of the 1980s, several extreme oxygen-depletion
events with hydrogen sulfide development and killing of fish and macrozoobenthos, as for example in the Belt Sea and the Western Baltic
(Ehrhardt and Wenck 1984; Weigelt and Rumohr 1986), initiated a
number of national governmental research projects in Denmark, Sweden
and Germany.
At the end of the 1960s, and increasingly from the end of the 1970s,
observations on changes of phytobenthic communities in the Baltic were
reported and related to human impact on the Baltic ecosystem
(Schwenke 1969; Ronnberg 1981; Kangas et al. 1982; Haathela 1984).
Institut fUr Meereskunde, UniversWit Kiel, Diisternbrooker Weg 20,24105 Kiel, Germany
Ecological Studies, Vol. 123
Schramm/Nienhuis (eds) Marine Benthic Vegetation
© Springer-Vedag Berlin Heidelberg 1996
W. SCHRAMM
5.1 Introduction
The Baltic Sea and its transition zones probably range among the most
encumbered marine waters around the world.
Bordered by nine countries, most of them densely populated and
highly industrialized, and not far away from the centres of air pollution
in Europe, this brackish inland sea is particularly endangered and susceptible to man made eutrophication and pollution due to its specific
hydrographical conditions and geomorphological features. During the
past two decades, an increasing number of observations have been made,
which indicate the response of the ecosystem Baltic to these man-made
impacts.
The international concern of the Baltic states about the alarming signs
and symptoms of pollution and eutrophication led to the Helsinki Convention on the protection of the Baltic environment (Baltic Marine Environment Protection Commission, HELCOM) in 1974.
Since the beginning of the 1980s, several extreme oxygen-depletion
events with hydrogen sulfide development and killing of fish and macrozoobenthos, as for example in the Belt Sea and the Western Baltic
(Ehrhardt and Wenck 1984; Weigelt and Rumohr 1986), initiated a
number of national governmental research projects in Denmark, Sweden
and Germany.
At the end of the 1960s, and increasingly from the end of the 1970s,
observations on changes of phytobenthic communities in the Baltic were
reported and related to human impact on the Baltic ecosystem
(Schwenke 1969; Ronnberg 1981; Kangas et al. 1982; Haathela 1984).
Institut fUr Meereskunde, UniversWit Kiel, Diisternbrooker Weg 20,24105 Kiel, Germany
Ecological Studies, Vol. 123
Schramm/Nienhuis (eds) Marine Benthic Vegetation
© Springer-Vedag Berlin Heidelberg 1996