|Central coordinates||6o 16.00' West 34o 51.00' North|
|IBA criteria||A1, A4i, A4iii|
|Altitude||0 - 30m|
|Year of IBA assessment||2001|
Site description Merja Zerga is a tidal lagoon located 70 km north of Kenitra on the Atlantic coast. The outlet to the ocean lies at the seaside resort and fishing village of Moulay Bou Selham: hence the site’s alternative name of Lagune de Moulay Bou Selham. In addition to its tidal inflow, the lagoon receives fresh water from the Oued Drader and the underlying water-table, which is very close to the surface here. The lagoon itself covers 4,500 ha, of which 30% is open water, and has an average depth of 1.5 m. Large mudbanks are exposed at low tide, providing extensive feeding areas for waders and waterfowl. Around the lagoon and included within the limits of the IBA are areas of rough pasture and marshland, and the Dayet Roureg, a freshwater pond. Vegetation consists mainly of salt-tolerant plants and shrubs such as Spartina sp., Sarcocornia perennis and Juncus rigidus. The annual rainfall of 600–700 mm, coupled with the low-lying nature of most of the site, result in the inundation in winter of large areas of land surrounding the lagoon proper.
Key Biodiversity See Box for key species. Merja Zerga is internationally renowned as a passage and wintering site for Palearctic migrants, and is without doubt the most important wetland site in Morocco. In total, over 100 species of bird regularly use Merja Zerga. An average of 15,000–30,000 ducks of 11 different species overwinter, as do approximately the same number of mixed Fulica atra and F. cristata. The lagoon also regularly holds 50,000–100,000 waders (19 regular species) and 1,000–2,000 Phoenicopterus ruber. Numenius tenuirostris was last recorded in 1995. There are also many resident breeding species including Asio capensis.
Non-bird biodiversity: Three endemic Moroccan lizards occur: Acanthodactylus lineomaculatus, Chalcides mionecton and C. pseudostriatus.
|Species||Season||Period||Population estimate||Quality of estimate||IBA Criteria||IUCN Category|
|Ruddy Shelduck Tadorna ferruginea||winter||-||250 individuals||-||A4i||Least Concern|
|Common Shelduck Tadorna tadorna||winter||-||4,700 individuals||-||A4i||Least Concern|
|Gadwall Mareca strepera||winter||-||1,350 individuals||-||A4i||Least Concern|
|Eurasian Wigeon Mareca penelope||winter||-||26,000 individuals||-||A4i||Least Concern|
|Northern Shoveler Spatula clypeata||winter||-||10,960 individuals||-||A4i||Least Concern|
|Marbled Teal Marmaronetta angustirostris||winter||-||30 individuals||-||A1, A4i||Vulnerable|
|Greater Flamingo Phoenicopterus roseus||winter||-||1,080 individuals||-||A4i||Least Concern|
|Red-knobbed Coot Fulica cristata||winter||-||67 individuals||-||A4i||Least Concern|
|Common Coot Fulica atra||winter||-||45,460 individuals||-||A4i||Least Concern|
|Pied Avocet Recurvirostra avosetta||winter||-||6,945 individuals||-||A4i||Least Concern|
|Grey Plover Pluvialis squatarola||winter||-||5,260 individuals||-||A4i||Least Concern|
|Slender-billed Curlew Numenius tenuirostris||winter||-||present||-||A1||Critically Endangered|
|A4iii Species group - waterbirds||winter||-||100,000-499,999 individuals||unknown||A4iii|
|2001||high||not assessed||not assessed|
|Good - based on reliable and complete / representative data|
|Agricultural expansion and intensification||livestock farming and ranching (includes forest grazing) - small-holder grazing, ranching or farming||happening now||majority/most of area/population (50-90%)||slow but significant deterioration||high|
|Human intrusions and disturbance||recreational activities||happening now||majority/most of area/population (50-90%)||slow but significant deterioration||high|
|Natural system modifications||dams & water management/use - abstraction of ground water (agricultural use)||happening now||majority/most of area/population (50-90%)||moderate to rapid deterioration||high|
|Over-exploitation, persecution and control of species||fishing & harvesting aquatic resources - unintentional effects: subsistence/small scale||happening now||majority/most of area/population (50-90%)||slow but significant deterioration||high|
|Over-exploitation, persecution and control of species||hunting & collecting terrestrial animals - intentional use (species being assessed is the target)||happening now||some of area/population (10-49%)||slow but significant deterioration||medium|
|Pollution||agricultural & forestry effluents - herbicides and pesticides||happening now||majority/most of area/population (50-90%)||slow but significant deterioration||high|
|Pollution||agricultural & forestry effluents - nutrient loads||happening now||majority/most of area/population (50-90%)||slow but significant deterioration||high|
|Protected area||Designation||Area (ha)||Relationship with IBA||Overlap with IBA (ha)|
|Merja Zerga||Biological Reserve||7,000||protected area contained by site||7,000|
|Merja Zerga||Wetlands of International Importance (Ramsar)||7,300||is identical to site||7,300|
|Land-use||Extent (% of site)|
|nature conservation and research||-|
|Notes: Egg collection.|
References BCEOM-SECA (1995c), El Agbani (1997), Zwarts (1972).
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Recommended citation BirdLife International (2015) Important Bird Areas factsheet: Merja Zerga. Downloaded from http://www.birdlife.org on 25/04/2015
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