الفهرس 
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Abstract
In general, many metals occur naturally in marine environments; some of them are classified as pollutants which are only when added by man in sufficient amounts to produce deleterious effects on some features of the ecological system. In aquatic systems, heavy metals have received considerable attention due to their toxicity and accumulation in biota. Heavy metals generally enter the aquatic environment through atmospheric deposition, erosion of the geological matrix, or due to anthropogenic activities caused by industrial effluents, domestic sewage, and mining wastes. Some of these metals, such as Cd and Pb, are toxic to living organisms even at quite low concentrations, whereas others, such as Zn and Cu, are biologically essential and natural constituents of aquatic ecosystems, and generally only become toxic at very high concentrations. The effects of heavy metals on human health and the environment are of great interest today, especially for aquatic products. The present work aimed to, study identification of the effect of heavy metals on marine fish cultures, recording the clinical signs and P.M lesions associated with such toxicity and finally monitoring of some heavy metal concentrations in both fish tissues and water that the fish live in it.
In this study we used about 480 fish (240 O. niloticus and 240 seabream) (Seabream Sparus aurata L.) that were collected showing clinical signs from private fish farms in Alexandria and behaira governorate, Egypt. The fish were subjected to full clinical, postmortem (PM) lesions, parasitic and mycological as well as bacteriological examinations.
The fish was grouped into: Experimental design and fish grouping: The fish in this study was divided into : The 1st attempt Group I: 10 O. niloticus fish that not take any treatment and considered as a control group. Group II: 10 seabream fish and considered as a control group.
Group III: 10 O. niloticus fish and treated with 9 X 102 CFU penicillum.
Group IV: 10 O. niloticus fish treated with 0.7 mg/L cadmium.
Group V: 10 Seabream fish treated with 9 X 102 CFU penicillum.
Group VI: 10 Seabream fish treated with 0.7 mg / L cadmium.
The length of the experiment was extended to 7 weeks.
The econd attempt Group I: 10 O. niloticus fish that not take any treatment and considered as a control group. Group II: 10 seabream fish and considered as a control group. Group III: 10 O. niloticus fish and treated with 9 X 102 CFU penicillum + 2 mg / L copper Group IV: 10 O. niloticus fish treated with 2 mg / L copper only.
Group V: 10 Seabream fish treated with 9 X 102 CFU penicillum.
+ 2 mg / L copper. Group VI: 10 Seabream fish treated with 2 mg / L copper only.