19 Satellite Surveys of Lagoon and Coastal Waters . . .
385
of about 50 km to the west and a main water body of about 30 km to the east,
ending with Zaranik pond. A long, arc-shaped, 300–1,000 m wide, low sand bar,
occasionally covered by water, separates the lagoon from the Mediterranean Sea.
An extensive sabkha
1 opens to the south, interrupted by series of sand dunes, with
ridges running parallel to the coast (Shaheen 1998). The Tineh Sabkha to the west
constitutes the eastern margin of the Nile Delta plain. There is little evidence that
the lake is a remnant of the estuary created by the easternmost Pelusiac branch
of the Nile, but undoubtedly the Nile supplied the large quantities of sand that formed
the bar separating the lagoon depression from the sea (Neev and Friedman 1978). At
present, seawater enters the lagoon through two artificial tidal inlets (i.e. Boughaze,
in the western and eastern parts of the lagoon, about 1 km long, 250–300 m wide,
and 4–7 m deep), kept open by periodic dredging, and the natural inlet of Zaranik,
at the eastern end, occasionally closed by silting. Being a concentration basin, with
no freshwater inflow, Lake Bardawil is the most saline of the northern Egyptian
lagoons. Its ecosystem depends on exchanges with the sea, which regulate salinity
and fish recruitment. It is considered to be one of the top fishing areas in Egypt,
although its production (1.500–2.500 t/year) accounted for less than 1 % of national
fish production in 2005 (GAFRD 2005).
19.2.2 Environmental Problems of the Egyptian Coastal Lagoons
The coast of northern Egypt, like all low-lying deltaic regions, is vulnerable to even
minor changes in shoreline processes. Any variation in sea level, due e.g. to climatic
deviations, is expected to have a pronounced impact on the Nile delta area and on
the lagoon ecosystems (El Fishawi and Fanos 1989; Frihy 1992; Stanley and Warne
1993). At present, the sand barriers separating the coastal lagoons from the sea are
undergoing intense erosion, due to the prevailing current and wave effects, and to the
absence of a steady sediment supply (resulting from the construction of the Aswan
High Dam in 1964). This shoreline retreat causes the lagoon barriers to reduce their
function as a natural protection line from the sea (Orlova and Zenkovich 1974; Fanos
et al. 1995). However, the coastal lagoons are also experiencing severe environmental problems due to increasing human pressure and interventions. Tampering with
coastal morphology, via the construction of artificial inlets associated with long jetties, to connect the lagoons with the Mediterranean Sea, has worsened local erosion
on the down drift side of adjacent beaches. Similar impacts are due to dredging of
the inlets, to prevent or remedy siltation taking place as a result of sand transport in
both longshore and cross-shore direction (Fanos et al. 1995).
In addition to natural processes, anthropogenic alterations have caused deep physical and ecological transformations in the lagoons. The rapid and uncontrolled urban
expansion in the whole region has changed shoreline stability and altered water
quality. Large parts of the deltaic lagoons have been drained for land reclamation
1 The word “sabkha” (a transliteration of the corresponding Arabic word) indicates a supratidal
coastal plain, normally covered by a salt crust.
385
of about 50 km to the west and a main water body of about 30 km to the east,
ending with Zaranik pond. A long, arc-shaped, 300–1,000 m wide, low sand bar,
occasionally covered by water, separates the lagoon from the Mediterranean Sea.
An extensive sabkha
1 opens to the south, interrupted by series of sand dunes, with
ridges running parallel to the coast (Shaheen 1998). The Tineh Sabkha to the west
constitutes the eastern margin of the Nile Delta plain. There is little evidence that
the lake is a remnant of the estuary created by the easternmost Pelusiac branch
of the Nile, but undoubtedly the Nile supplied the large quantities of sand that formed
the bar separating the lagoon depression from the sea (Neev and Friedman 1978). At
present, seawater enters the lagoon through two artificial tidal inlets (i.e. Boughaze,
in the western and eastern parts of the lagoon, about 1 km long, 250–300 m wide,
and 4–7 m deep), kept open by periodic dredging, and the natural inlet of Zaranik,
at the eastern end, occasionally closed by silting. Being a concentration basin, with
no freshwater inflow, Lake Bardawil is the most saline of the northern Egyptian
lagoons. Its ecosystem depends on exchanges with the sea, which regulate salinity
and fish recruitment. It is considered to be one of the top fishing areas in Egypt,
although its production (1.500–2.500 t/year) accounted for less than 1 % of national
fish production in 2005 (GAFRD 2005).
19.2.2 Environmental Problems of the Egyptian Coastal Lagoons
The coast of northern Egypt, like all low-lying deltaic regions, is vulnerable to even
minor changes in shoreline processes. Any variation in sea level, due e.g. to climatic
deviations, is expected to have a pronounced impact on the Nile delta area and on
the lagoon ecosystems (El Fishawi and Fanos 1989; Frihy 1992; Stanley and Warne
1993). At present, the sand barriers separating the coastal lagoons from the sea are
undergoing intense erosion, due to the prevailing current and wave effects, and to the
absence of a steady sediment supply (resulting from the construction of the Aswan
High Dam in 1964). This shoreline retreat causes the lagoon barriers to reduce their
function as a natural protection line from the sea (Orlova and Zenkovich 1974; Fanos
et al. 1995). However, the coastal lagoons are also experiencing severe environmental problems due to increasing human pressure and interventions. Tampering with
coastal morphology, via the construction of artificial inlets associated with long jetties, to connect the lagoons with the Mediterranean Sea, has worsened local erosion
on the down drift side of adjacent beaches. Similar impacts are due to dredging of
the inlets, to prevent or remedy siltation taking place as a result of sand transport in
both longshore and cross-shore direction (Fanos et al. 1995).
In addition to natural processes, anthropogenic alterations have caused deep physical and ecological transformations in the lagoons. The rapid and uncontrolled urban
expansion in the whole region has changed shoreline stability and altered water
quality. Large parts of the deltaic lagoons have been drained for land reclamation
1 The word “sabkha” (a transliteration of the corresponding Arabic word) indicates a supratidal
coastal plain, normally covered by a salt crust.