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Location Morocco, Kenitra
Central coordinates 6o 16.00' West  34o 51.00' North
IBA criteria A1, A4i, A4iii
Area 7,300 ha
Altitude 0 - 30m
Year of IBA assessment 2001





Ornithological information 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.

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.

Populations of IBA trigger species

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 Anas strepera winter  1,350 individuals  A4i  Least Concern 
Eurasian Wigeon Anas penelope winter  26,000 individuals  A4i  Least Concern 
Northern Shoveler Anas 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 [units unknown]  A1  Critically Endangered 
A4iii Species group - waterbirds winter  unknown  A4iii   

Protected areas

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

Land-use Extent (% of site)
agriculture -
fisheries/aquaculture -
hunting -
nature conservation and research -
tourism/recreation -
urban/industrial/transport -
other -
Notes: Egg collection.

Other biodiversity Three endemic Moroccan lizards occur: Acanthodactylus lineomaculatus, Chalcides mionecton and C. pseudostriatus.

Management considerations The lagoon of Merja Zerga was classified as a Permanent Biological Reserve in 1978, and nominated as a Ramsar Site in 1980. It is a priority 1 SIBE (No. L16). Publicly owned, the site is managed by several government agencies: Ministères de l’Agriculture, des Pêches Maritimes, des Habous and de l’Intérieur. A hunting concession is located on the boundaries of the IBA at Merja Kahla. Human activities include fishing, harvesting of shellfish, livestock-rearing, hunting and tourism (including birdwatching). Threats include illegal poaching and egg-collecting, over-fishing and overgrazing, excessive exploitation of groundwater for use in irrigated cultivation projects around the lagoon’s shores, pollution from pesticide and fertilizer run-off from surrounding agricultural land, increasing levels of tourism, and disturbance from the newly constructed motorway on the eastern bank of the lagoon. The area urgently requires the implementation of a coordinated management plan.

References BCEOM-SECA (1995c), El Agbani (1997), Zwarts (1972).

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Recommended citation  BirdLife International (2013) Important Bird Areas factsheet: Merja Zerga. Downloaded from http://www.birdlife.org on 24/05/2013

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