Lake Manzala, the largest of Egypt’s Mediterranean wetlands and the most productive for fisheries, is located in the north-eastern corner of the Nile delta. Manzala is generally rectangular in shape, about 60 km long and 40 km wide, and has an average depth of 1.3 m. It is separated from the Mediterranean Sea by a sandbar, through which it is connected to the sea by three channels (bughaz). The salinity in the lake varies greatly; while it is low near drain and canal outflows in the south and west, it is high in the extreme north-west. Brackish conditions predominate over much of the remainder of the lake. Over 1,000 islands of varying sizes are scattered throughout the lake.The three main habitats are reed-swamps, saltmarshes and sandy areas. The reed-swamps of Phragmites and Typha, with associated submerged water-plants (e.g. Potamogeton and Najas), are found extensively in the less saline portions of the lake in the south and west and fringing many islands. Saltmarshes of Juncus and Halocnemum occur on the northern (coastal) margins of the lakes and some islands. Sand formations are occupied by several plant communities, e.g. coastal dunes. Open water and mudflats are also important habitats for birds. Large areas in the north-west of the lake have been turned into fish-farms, while much of the southern part of the site (south of 31°10 N) has been divided into large plots and drained, in preparation for its conversion to agricultural use.A total of 3.7 km³ of fresh water (mostly from agricultural drainage) flow annually into Lake Manzala from nine major drains and canals. The most important of these are Faraskur, Al Sarw, Baghous, Abu Garida and Bahr El Baqar. Of all the drains discharging into Lake Manzala, the Bahr El Baqar drain is the most polluted. It carries a mixture of treated and untreated waste-water originating from Cairo and contributing much to the deteriorating water quality of the lake. Bughaz El Gamil is the main connection between the lake and the Mediterranean. Several other less important sea connections have recently been enlarged.
See Box for key species. Manzala is by far the most important wetland for wintering waterbirds in Egypt, holding a total of 233,901 waterbirds in winter 1989/90. This represented c.40% of all waterfowl counted throughout Egypt’s wetlands that winter and included the world’s largest concentrations of wintering Larus minutus and Chlidonias hybridus. There were also up to 36,180 waders present in spring 1990, indicating the great importance of the wetland for populations of passage migrants, especially of Recurvirostra avosetta, Calidris minuta, Calidris alpina and Philomachus pugnax. No similar counts are available for autumn, but the lake is likely to be as important in that season. Manzala is also of importance for a number of breeding waterbirds and wetland species. About 35 species are known to breed, including Ixobrychus minutus, Egretta garzetta, Ardeola ralloides, Porphyrio porphyrio, Sterna albifrons, Charadrius alexandrinus, Vanellus spinosus, Glareola pratincola, Caprimulgus aegyptius, Ceryle rudis and Acrocephalus stentoreus. For some of these species, Manzala is one of the most important breeding areas in the entire western Palearctic region.
Non-bird biodiversity: Reptiles: The Mediterranean shore of the lake is a potential breeding site for endangered marine turtles. Caretta caretta (EN)is the species most likely to breed in the area. Mammals: Felis chaus is still known to occur in good numbers.
Pressure/threats to key biodiversity
The lake is unprotected, apart from Ashtum El Gamil Protected Area (declared by Prime Ministerial Decree 459/1988), which encompasses a small area (c.35 km²) located along the sandbar at Bughaz El Gamil, the largest connection between the lake and the sea, near Port Said. The main purpose for creating this protected area was the protection of gravid fish and fry during their passage in and out of Manzala, through Bughaz El Gamil. Ashtum El Gamil includes no suitable waterfowl habitat, nor is it large enough to be of any significance for the conservation of the vast majority of Manzala’s resident and transient avifauna. However, there is a proposal to increase the size of this protected area to encompass larger, more important parts of Lake Manzala.At the beginning of the century the lake covered some 1,698 km². However, ambitious land-reclamation projects had reduced the size of the lake to 905 km² by 1981 and to 770 km² by 1988. It is predicted that existing reclamation plans will reduce its area further to 469 km². Encroachment from adjacent urban centres is threatening to reduce the area of the lake even further. Since the construction of the High Dam and the almost complete cessation of sedimentation, the coasts of the eastern delta have altered from predominantly accretional to erosional. The rapid erosion of the coast of Lake Manzala and encroachment of the sea in a region which, during the late Holocene, had been expanding northwards at an average rate of about 10 m per year, is of concern.The implementation of the El Salam Canal project and theNSADP will require the annual diversion of c.1.27 km³ of water from the delta (currently mostly destined for Manzala). This is expected to lead to a significant increase in the salinity of the lake from the current 3 g/l to 8 g/l, consequently changing its whole ecology. The present Bughaz El Gamil will be far too small to safeguard the present water-level. Without large infrastructural works, it can be expected that much of the lake will turn into a very shallow brackish marsh, with much of the extensive reed-swamp (and associated avifauna) declining sharply or disappearing altogether.The pollution problem is very severe and is caused by many factors. Municipal waste-water is, perhaps, the most serious source of pollution, as much of the raw and treated sewage from Cairo, Port Said and Damietta ends up in Manzala. Industrial waste-water is also discharged into the lake from various sources, including industrial areas north of Cairo. Sewage-treatment projects for Cairo, once online, should help to alleviate some of the pollution. In addition, agricultural drainage water, which makes up most of the fresh water entering the lake, has high concentrations of fertilizers and pesticides. Solid waste from adjacent urban centres is regularly dumped into the lake and used for land-fill.Highly organized bird-catching activities take several tens of thousands of waterfowl every year, mainly ducks, Fulica atra, Gallinula chloropus and waders. In spring 1990 a total of 11,709 birds (presumably, mostly from Manzala and its environs) were found for sale in bird markets in Port Said and Damietta. The impact of these activities on waterfowl populations is not known. It is probably a less significant threat than that posed by the deterioration and eventual loss of Manzala’s habitats.
BirdLife International (2020) Important Bird Areas factsheet: Lake Manzala. Downloaded from
http://www.birdlife.org on 25/05/2020.