The lakes and wetlands of the Mediterranean Delta coast form an important eco-zone especially for migrating and wintering water birds.
Lake Maryut, just south of Alexandria, has no direct connection to the sea and lies at 2.8m below sea level. Agricultural drainage water enters the lake through canals causing the water level to rise and to maintain the level, excess water is pumped out into the sea. To the west of the lake is a large saltmarsh that was formerly part of the lake but was separated from it when the railway line was constructed in 1858.
East of Lake Maryut is Lake Idku, the northern shore of which is covered with sand dunes except for a single gap that connects it to the sea. The salinity of this lake is relatively high but where agricultural water drains into it in its southern part the water is only slightly brackish. There are many small islands in Lake Idku and an extensive marsh has developed where the drainage canals enter.
Lake Burullus is located slightly east of the Rosetta branch of the Nile and is extremely shallow, varying from 0.75m to 1m in depth. The eastern portion of this rather elongated lake is the shallowest and there are about 50 small islands scattered throughout its area. The sand bar that separates the lake from the sea varies in width from a few hundred meters in the east to about 5km at the western end. The only connection between the lake and the sea is at the northeast corner and here the water is most saline. The salinity decreases to the south and the water is fresh near the canals and drains that enter the lake. Commercial salt production and fish farming are carried on to the south of the lake where there are salt marshes.
Lake Manzala, east of Damietta, is the largest of the Delta lakes and has most connections with the sea. The salinity is highest in the northwest and lowest near the drain and canal inflows on the south and east. The rest of the lake is brackish. There are over 1000 islands scattered throughout the lake and fish farms take up large areas of its northwest.
The shallowest of the
lakes is Lake Mallaha/Bur Fuad. It is only 10-20cm deep
with a soft muddy bottom and receives no Nile water
but is connected to the sea. There are extensive areas
of sabkha round it.
The extremely saline
Lake Bardawil is an important feature of the north coast
of Sinai and stretches along much of its length. The
lake is separated from the Mediterranean by a low sandbar
that is between 100m and 1km wide and is often covered
by seawater. The sandy bottom of this shallow lake (0.5-3.0m)
is covered by patches of the ditch grass, Ruppia
spiralis and there is a number of islands. Lake
Bardawil is important for its fishery of up to 2500
tonnes annually, mostly of such high-value fish as Gilthead,
Sparus auratus, and Mullet, Mugil
sp. In the immediate vicinity of the lake Little Tern,
Sterna albifrons, and Kentish Plover, Charadrius
alexandrinus, are found in internationally important
numbers.
Most of the lakes support extensive reed swamps of Typha and Phragmites and areas of halophytic vegetation. Lake Manzala contains submerged aquatic plants such as Najas armata and the Pondweed, Potamogeton pectinatus.
Many thousands of birds winter on these lakes and include Gulls (Larus minutus and L. ridibundus among others), Greater Flamingo, Phoenicopterus ruber, and White-breasted Cormorant, Phalacrocorax carbo. Lake Manzala is the most important wetland in Egypt for wintering waterbirds and for some breeding species is one of the most important areas in the Western Palearctic.
The Green Toad, Bufo
viridis, is found in somewhat brackish water, while
Bufo kassasii is a freshwater species. Tessellated
Water Snake, Natrix tessellata, has been recorded
in freshwater marshes; Bridled Skink, Mabuya vittata,
occurs round freshwater and brackish water marshes.
Swamp Cat, Felis chaus, is known to occur in
Phragmites and Typha reed swamps and
other shore vegetation at some of the lakes.
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