الفهرس 
Chapter One: INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
The materials of this study were collected from Manzala Lagoon. These materials consist of 30 bottom sediment samples. Some parameters are measured such as pH, salinity, water depth and grain size. The distribution of trace metals and recent benthic foraminifera are examined.
The recorded water depths of the study area vary between 53 cm and 250 cm with an average of 162.9 cm, indicating that lagoon is shallow. Salinity ranges from 1.23 g/l to 20.6 g/l with an average of 6.1 g/l. The salinity increases towards El-Boughaz inlet in the northern parts, while it decreases towards the southern parts. The values of pH range from 7.12 to 9.11 with an average of 8.09. Therefore, the water is alkaline.
The bottom sediments of Manzala Lagoon contain a mixture of clay, silt and sand. The percentages of sand fractions range from 5% to 66% with an average of 30.2 %. The percentages of silt fractions range from 30% to 44% with an average of 37.13 %. The percentages of clay fractions fluctuate between 3% and 59% (with an average of 32.6 %. Near the northern sites.
The measured trace metals from the bottom sediments of Manzala Lagoon include Cu, Zn, Pb, Mn, Cd and Ni. Generally, the maximum levels of trace metals were noted near the southern drains and decrease in the norrthen sites, owing to the entrance of the industrial disposal and agricultural drainage water into the lagoon for a long time without treatment. Based on the average values of the contamination factor, the measured trace metals are in the order Cd > Pb > Ni > Cu > Zn > Mn. All sites display very high Dc, where the values are more than 28. The values of PLI range from 1.43 to 4.74 with an average of 2.83, indicating that all sites are polluted. According to the values of Er, the contaminants are arranged as follows Cd > Pb > Ni > Cu > Zn > Mn. All sites display very high values of Ri.
The investigated foraminiferal community consists of eight species, belonging to 6 genera (Adelosina, Quinqueloculina, Miliolinella, Triloculina, Ammonia and Cribroelphidium). In general, the hyaline species dominate all the sites, while porcelanaceous species are concentrated only in the north eastern sites. Ammonia beccarii dominates all the studied sites, reflecting its tolerance to very low salinity. In this study, the documented morphological deformities are expressed as: spiroconvexity, additional chambers, twisting, reduced chamber, aberrant chamber size and shape, twinning and complex deformities.