الفهرس 
LITERATURE REVIEWOnly 14 pages are availabe for public view
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Abstract
Physico-chemical parameters of the main basin of Lake Maruit, Qalaa Drain and its branches were studied during summer 2013 and winter 2014. All the recorded values are higher than that recorded previously and the international as well as Law 48/1982 limits for fresh water protection guidelines. Water and sediment qualities in Qalla drain and its branched drains network, especially Nazar Drain – the highly polluted locations, caused deterioration of sediment and water quality in the main basin of Lake Maruit. Moreover, 16 heavy metals were studied in water hyacinth (Eichornia crassipes) leaves, stems, and roots. It absorbs heavy metals from the effluent and it has a tendency to accumulate trace metals in its leaves, shoots and roots. Gastropods, especially pulmonates and bivalves were dominated in different study areas, as they are pollution tolerant molluscs.
Diversity indices of phytoplankton and zooplankton; species richness, evenness, Shannon and Simpson indices were statistically calculated. Significant difference with confidence intervals is 95% with P<0.05 were measured.
Diatoms and Cyanophyceae genera (phytoplankton), Rotifera and Copepoda (zooplankton) were recorded as good biological indicators for water organic pollution, these genera were correlated statistically with COD, DO, BOD, Ammonia, and Coliform bacteria.
For molluscs, puluonates were dominant in the study area. They are pollution tolerance species. They can be used as bioindicators for pollution of aquatic ecosystems. Fish did not appeared in the field visits in most of the study area, only Tilpia sp. was recoded as the main fish in fishermen catchments.
Most locations in the study area were displayed low plankton biodiversity due to water quality deterioration and high loads of nutrients. Qalla Drain water quality was classified as bad and very bad in most of the study locations and these caused deterioration of Lake Maruit water quality and fisheries in the lake.
Because of the importance of the Lake Maruit to the country fishery, as well as to resident migratory and wintering birds, it is recommended that conservatory measures should be implemented to preserve and revive this vital important ecosystem.