529
improvement of the quality of these soils; these include desiccation/drainage, soil
salinization prevention and control, land leveling, soil texture homogenization, soil
acidity problems, and reed removal problems.
The hydrological factor is the main aspect that disturbed the ecosystems of the
spaces that were altered for agricultural purposes during the communist regime. The
changes in the natural hydrological regime brought about by dykes have resulted in
a series of physical and chemical changes in the soils and in the vegetation structure.
In turn, these changes triggered changes in local fish and bird fauna habitats. The
main alterations that were carried out here were damming and construction of a
network of desiccation canals (hence, a substantial modification of the water circuit
in these areas) and the replacement of wetland plants with agricultural crops, leading to profound changes in the vegetation structure and composition, marsh soil
degradation (organic matter loss), increased soil salinity, reduction in the number of
bird habitats, and loss of the filtration role of sediments and nutriments.
In the areas of concern, forestry developments are quite small in comparison to
agricultural developments; the former only occupy 4650 ha. Canadian poplar plantations (Populus canadensis) are present in the Papadia, Rusca, Carasuhat, Pardina
and Murighiol developments or along the main Danube branches. These plantations
have reduced flower diversity, reflecting reduced delta biodiversity, and have led to
the degradation of the forest ecosystems, especially those of the Letea and
Caraorman forests.
All these developments, together with the full delta resources exploitation policy,
have also stimulated the construction of canals around these facilities of economic
interest. Examples of such canals include the Crisan-Caraorman canal connecting
the Sulina branch and the Caraorman locality, where a sand exploitation facility was
designed (nevertheless, this industrial facility was never built), the 10-km Mila 35
canal connecting the Tulcea and Chilia branches, which allows communication with
and transportation to localities along the Chilia branch, other branch-straightening
works designed to facilitate reed transportation, water supply in the fish farming
developments and water supply for irrigation purposes. One of the last large changes
during the communist regime occurred on the Sfantu-Gheorghe branch, which was
straightened between 1985 and 1990; during this process, its length was reduced by
38 km from its original length of 108 km. The straightening of the branch, which
was accomplished by shortcutting six meanders, has increased the water flow; consequently, the sediment flow has helped reduce the erosion of the southern coastline
at the mouth of the branch.
The communist regime has left deep “scars” on the delta. The desire to exploit at
all costs the deltaic resources has led to gigantic and ambitious projects that were
disproportionate in comparison to the natural and fragile space represented by the
delta. These projects displayed no regard whatsoever for the ecological component
and for the natural balance, the only goal being economic development. Nevertheless,
the natural balance preservation problems raised by delta resources exploitation
17 Alteration and Remediation of Coastal Wetland Ecosystems in the Danube Delta…
improvement of the quality of these soils; these include desiccation/drainage, soil
salinization prevention and control, land leveling, soil texture homogenization, soil
acidity problems, and reed removal problems.
The hydrological factor is the main aspect that disturbed the ecosystems of the
spaces that were altered for agricultural purposes during the communist regime. The
changes in the natural hydrological regime brought about by dykes have resulted in
a series of physical and chemical changes in the soils and in the vegetation structure.
In turn, these changes triggered changes in local fish and bird fauna habitats. The
main alterations that were carried out here were damming and construction of a
network of desiccation canals (hence, a substantial modification of the water circuit
in these areas) and the replacement of wetland plants with agricultural crops, leading to profound changes in the vegetation structure and composition, marsh soil
degradation (organic matter loss), increased soil salinity, reduction in the number of
bird habitats, and loss of the filtration role of sediments and nutriments.
In the areas of concern, forestry developments are quite small in comparison to
agricultural developments; the former only occupy 4650 ha. Canadian poplar plantations (Populus canadensis) are present in the Papadia, Rusca, Carasuhat, Pardina
and Murighiol developments or along the main Danube branches. These plantations
have reduced flower diversity, reflecting reduced delta biodiversity, and have led to
the degradation of the forest ecosystems, especially those of the Letea and
Caraorman forests.
All these developments, together with the full delta resources exploitation policy,
have also stimulated the construction of canals around these facilities of economic
interest. Examples of such canals include the Crisan-Caraorman canal connecting
the Sulina branch and the Caraorman locality, where a sand exploitation facility was
designed (nevertheless, this industrial facility was never built), the 10-km Mila 35
canal connecting the Tulcea and Chilia branches, which allows communication with
and transportation to localities along the Chilia branch, other branch-straightening
works designed to facilitate reed transportation, water supply in the fish farming
developments and water supply for irrigation purposes. One of the last large changes
during the communist regime occurred on the Sfantu-Gheorghe branch, which was
straightened between 1985 and 1990; during this process, its length was reduced by
38 km from its original length of 108 km. The straightening of the branch, which
was accomplished by shortcutting six meanders, has increased the water flow; consequently, the sediment flow has helped reduce the erosion of the southern coastline
at the mouth of the branch.
The communist regime has left deep “scars” on the delta. The desire to exploit at
all costs the deltaic resources has led to gigantic and ambitious projects that were
disproportionate in comparison to the natural and fragile space represented by the
delta. These projects displayed no regard whatsoever for the ecological component
and for the natural balance, the only goal being economic development. Nevertheless,
the natural balance preservation problems raised by delta resources exploitation
17 Alteration and Remediation of Coastal Wetland Ecosystems in the Danube Delta…