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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

Groupe de Recherche pour la Protection des Oiseaux au Maroc (Affiliate)

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.

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 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   

IBA Monitoring

2001 high not assessed not assessed
Good - based on reliable and complete / representative data

Agriculture and aquaculture 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
Biological resource use fishing & harvesting aquatic resources - unintentional effects: subsistence/small scale happening now majority/most of area/population (50-90%) slow but significant deterioration high
Biological resource use 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
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
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 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.

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

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Recommended citation  BirdLife International (2016) Important Bird and Biodiversity Area factsheet: Merja Zerga. Downloaded from on 29/10/2016

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