An ecological survey of standing waters in North West Africa: I. Rapid survey and classification

Morgan, Nigel; Boy, Vincent

doi:10.1016/0006-3207(82)90045-3

Cited by 30 publications

(21 citation statements)

References 5 publications

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“…1b), has also received considerable attention regarding water quality and plankton and the large migrant bird populations (Morgan & Boy, 1980;Daly Yahia & Romdhane, 1994;Souissi et al, 2000;Daly Yahia et al, 2001;Benrejeb-Jenhani & Romdhane, 2002). The lagoon, which has a total area of approximately 35.6 km 2 , is separated from the Mediterranean by sand bars through which there is one main and several smaller connections to the sea.…”

Section: Sites Materials and Methodsmentioning

confidence: 96%

Environmental influences on the qualitative and quantitative composition of phytoplankton and zooplankton in North African coastal lagoons

Ramdani¹,

Elkhiati

Flower

et al. 2009

Hydrobiologia

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Within the framework of the international research project MELMARINA, seasonal dynamics of plankton communities in three North African coastal lagoons (Merja Zerga, Ghar El Melh, and Lake Manzala) were investigated. The sampling period extended from July 2003 to September 2004 with the aim of evaluating hydrological and other influences on the structure, composition and space-time development of these communities in each lagoon. Phytoplankton in Merja Zerga showed a quasi-permanent predominance of marine diatoms in the open sea station and in the marine inlet channel. Dinoflagellates were abundant in summer and early autumn in the marine inlet and extended into the central lagoon station. In Ghar El Melh, marine species (especially diatoms and dinoflagellates) dominated despite occasional winter inflows of freshwater. In Lake Manzala, freshwater species generally predominated and the planktonic communities were comparatively very diverse. Chlorophyceae contributed 39% of the total species recorded and diatoms and cyanophyceans were also common; the Dinophyceae, Euglenophyceae, Chrysophyceae and Cryptophyceae less so. Zooplankton communities in both Ghar El Melh and Merja Zerga were dominated by marine copepods. Rotifera, Copepoda, Ostracoda, and Cladocera were recorded in both lagoons as were meroplanktonic larvae of Polychaeta, Cirripedia, Mysidacea and Gastropoda and free living nematodes. Ghar El Melh was the more productive of these two lagoons with spring and early summer being the productive seasons. Zooplankton communities in Lake Manzala were generally dominated by rotifers and highest zooplankton abundances occurred in April (2003). Sampling stations near the marine inlets showed the highest diversity and the zooplankton communities showed considerable spatial variation within this large lagoon. The three lagoons represent very different water bodies contrasted strongly in terms of tidal effects and freshwater availability. Yet, there are some similarities in ecosystem structure. Space-time development of the plankton communities was similar especially in Merja Zerga and Ghar El Melh. Species abundances and specific diversities indicated that seasonal changes in salinity and nutrient concentrations were the main influential factors. Lake Manzala was the most productive lagoon and all the three sites supported toxic algal species. Relatively low plankton biomass in Merja Zerga and Ghar El Melh probably resulted from a combination of factors including highly episodic nutrient inputs, light suppression (by turbidity) and nutrient competition with benthic algae. Water quality variables were largely driven by the hydrological regime specific to each lagoon. Nutrient enrichment and, particularly for Lake Manzala, sea level rise threaten the sustainability of the planktonic ecosystems in all three lagoons.

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Section: Sites Materials and Methodsmentioning

confidence: 96%

Environmental influences on the qualitative and quantitative composition of phytoplankton and zooplankton in North African coastal lagoons

Ramdani¹,

Elkhiati

Flower

et al. 2009

Hydrobiologia

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“…Under these existing, modified, hydrological conditions, Merja Zerga can be classified as a marine wetland since the basin is now permanently tidal (Morgan, 1982;Green et al, 2002). As demonstrated by Thompson et al (2009), the tidal influence is strongly attenuated in the southern sector away from the ''gullet''.…”

Section: Hydro-geomorphological Characteristics Of Merja Zergamentioning

confidence: 95%

Environmental characteristics, landscape history and pressures on three coastal lagoons in the Southern Mediterranean Region: Merja Zerga (Morocco), Ghar El Melh (Tunisia) and Lake Manzala (Egypt)

et al. 2009

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“…The classifications used in these inventories are mostly linear and non-hierarchical, so that large wetland systems are ascribed to several classes. Morgan and Boy (1982), however, describe hierarchical classification, based on multivariate analysis, for North African Table 2. Classification of wetlands used in Italian wetland inventory (1972, unpublished wetlands.…”

Section: Wetland Inventory and Classificationmentioning

confidence: 99%

“…Britton and Podlejski (1981) for the RhOne Delta, MOPU (1984) for the Andalucia region of Spain), or are obviously incomplete (e.g. Dorikos (1981) for Greece, Morgan and Boy (1982) for North Africa).…”

Section: Wetland Inventory and Classificationmentioning

confidence: 99%

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Wetlands of southern Europe and North Africa: Mediterranean wetlands

Britton¹,

Crivellì²

1993

Wetlands of the World: Inventory, Ecology and Management Volume I

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Wetlands of the south of Europe and north Africa extend from Bulgaria to the Iberian peninsula, and from Tunisia to Morocco. The three main environmental factors explaining the distribution of the wetlands are: climate, topography and geology, and tides. The principal geomorphological formations containing wetlands are described in detail and numerous examples are given. They are: river deltas, coastal lagoons, riverine floodplains, inland freshwater lakes, man-made reservoirs, athalassic salt basins, intertidal systems, permanent river channels, and seasonally-flooded river channels. Many inventories and classifications of wetlands of the region have been carried out, but few of them are comparable. A new classification is proposed for the whole study area. The factors determining the ecological characteristics of the emergent and submerged vegetation of Mediterranean wetlands are identified and their impacts on the composition of the vegetation are analyzed in detail. Six vegetation categories have been determined: halophytic vegetation, emergent reedswamp communities, riverine forests, dwarf rush communities, and submerged and floating vegetation of freshwater habitats. Invertebrates, fish, birds, and mammals occurring in Mediterranean wetlands are listed and the factors responsible for their presence or absence are analyzed. As a general rule, birds are very well known, but information on invertebrates, fish, and mammals is still poor. The usage of and conservation problems of Mediterranean wetlands show that most of them are overexploited and degraded, and few are protected. Many organisms depending on these wetlands are nowadays threatened with extinction. Although the distribution and size of the Mediterranean wetlands is well known, the functioning of the ecosystems in the Mediterranean region remains poorly understood. This is a major handicap at the moment, when ways of better managing or even restoring certain Mediterranean wetlands are being talked of.

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An ecological survey of standing waters in North West Africa: I. Rapid survey and classification

Cited by 30 publications

References 5 publications

Environmental influences on the qualitative and quantitative composition of phytoplankton and zooplankton in North African coastal lagoons

Environmental influences on the qualitative and quantitative composition of phytoplankton and zooplankton in North African coastal lagoons

Environmental characteristics, landscape history and pressures on three coastal lagoons in the Southern Mediterranean Region: Merja Zerga (Morocco), Ghar El Melh (Tunisia) and Lake Manzala (Egypt)

Wetlands of southern Europe and North Africa: Mediterranean wetlands

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