The Baltic Sea and Its Transition Zones
139
are common, and in the western Baltic, Laminaria beds can be found up
to the Darss sill. In terms of extension and biomass, the red algal communities are certainly the most important phytobenthic systems in the
Baltic, penetrating as far as the Aland Sea. The dominant species may
occur in rather homogeneous populations, however, they mostly form
mixed communities of red and brown algae.
Many of the stenohaline forms show size reduction, as for example
Delesseria sanguinea, which together with Phycodrys rubens or
Polysiphonia stricta, reach their northern boundary in the Baltic proper.
Loose lying forms of Phyllophora pseudoceranoides or Furcellaria lumbricalis penetrate into the Bothnian Bay or the Gulf of Finland till the
lower mesohaline borderline. In the innermost parts of the Baltic, including the Gdansk Bay and the German inshore "Bodden" waters, under
oligohaline conditions (3-0.5 PSU) marine algae such as Blidingia minima, Bangia atropurpurea or species of Enteromorpha can be found.
Laminaria saccharina and L. digitata together with Desmarestia aculeata,
Ascophyllum nodosum and Chondrus cripus penetrate in size-reduced form
not further into the Baltic than the Darss sill, the western border of the
Arcona Sea. Like Fucus, the community forming Laminaria grow only
submerged.
5.4 Eutrophication and Pollution Situation
This book is, on the first hand, concerned with the changes in phytobenthic communities as a result of eutrophication. Therefore, in this chapter,
focus will be on changes in inorganic nutrient levels in the Baltic, although it cannot be excluded that other factors, either natural or manmade, may also have affected the phytobenthos (Wallentinus 1981).
While little is known about natural medium- or long-term fluctuations in
the structure and function of marine systems, as for example as a result
of climatic or hydrographic changes, local effects of pollutants such as
heavy metals, toxic organic compounds and other harmful substances,
heat or dumping of solid materials have been observed.
Despite the fact that the Baltic Sea is one of the most intensively
studied sea areas in the world, it is difficult to obtain a comprehensive
up-to-data picture of the present pollution and eutrophication situation.
The complex interaction of biological, chemical, physico- and geochemical processes in combination with the specific hydrographic conditions
in the Baltic makes it difficult to quantify the actual eutrophication and
139
are common, and in the western Baltic, Laminaria beds can be found up
to the Darss sill. In terms of extension and biomass, the red algal communities are certainly the most important phytobenthic systems in the
Baltic, penetrating as far as the Aland Sea. The dominant species may
occur in rather homogeneous populations, however, they mostly form
mixed communities of red and brown algae.
Many of the stenohaline forms show size reduction, as for example
Delesseria sanguinea, which together with Phycodrys rubens or
Polysiphonia stricta, reach their northern boundary in the Baltic proper.
Loose lying forms of Phyllophora pseudoceranoides or Furcellaria lumbricalis penetrate into the Bothnian Bay or the Gulf of Finland till the
lower mesohaline borderline. In the innermost parts of the Baltic, including the Gdansk Bay and the German inshore "Bodden" waters, under
oligohaline conditions (3-0.5 PSU) marine algae such as Blidingia minima, Bangia atropurpurea or species of Enteromorpha can be found.
Laminaria saccharina and L. digitata together with Desmarestia aculeata,
Ascophyllum nodosum and Chondrus cripus penetrate in size-reduced form
not further into the Baltic than the Darss sill, the western border of the
Arcona Sea. Like Fucus, the community forming Laminaria grow only
submerged.
5.4 Eutrophication and Pollution Situation
This book is, on the first hand, concerned with the changes in phytobenthic communities as a result of eutrophication. Therefore, in this chapter,
focus will be on changes in inorganic nutrient levels in the Baltic, although it cannot be excluded that other factors, either natural or manmade, may also have affected the phytobenthos (Wallentinus 1981).
While little is known about natural medium- or long-term fluctuations in
the structure and function of marine systems, as for example as a result
of climatic or hydrographic changes, local effects of pollutants such as
heavy metals, toxic organic compounds and other harmful substances,
heat or dumping of solid materials have been observed.
Despite the fact that the Baltic Sea is one of the most intensively
studied sea areas in the world, it is difficult to obtain a comprehensive
up-to-data picture of the present pollution and eutrophication situation.
The complex interaction of biological, chemical, physico- and geochemical processes in combination with the specific hydrographic conditions
in the Baltic makes it difficult to quantify the actual eutrophication and