الفهرس 
Introduction
Statistical analysisOnly 14 pages are availabe for public view
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Abstract
The present study illustrates the evaluation of some pollutants in the River Nile estuaries and its influence on the marine environment throughout the period from autumn 1999 to summer 2000. Twelve sites were selected representing the studied sites of the River Nile estuaries (Six sites for each Damietta and Rosetta Branches).
A- Damietta Branch (I- Damietta Estuary Mouth, II- EL Gerby, III- Navigation canal, IV- El Aasar, V- Front of Faraskour Dam (Brackish water) and VI- Behind of Faraskour Dam (Fresh water)).
B- Rosetta Branch (I- Rosetta Estuary Mouth, II- EL Geddia, III- El Hessa, IV- Madea Mahdy, V- Front of Edfina Dam (Brackish water) and VI- Behind of Edfina Dam (Fresh water)).
The study included the physico-chemical characteristics in water and sediments, also, determination of Pb, Cu, Zn and Fe in water, sediment and some organs (muscle, liver and gills) of selected species of fishes (Tilapia zillii and Liza ramada) inhabiting these sites. The results showed that the means of surface water temperature in Damietta and Rosetta estuaries were 24.18 ± 1.44 C and 25.75 ± 1.19 C, respectively; the average of turbidity in Damietta and Rosetta estuaries were 3.79 ± 0.3 NTU and 4.56 ± 0.2 NTU, respectively. The average of pH values in Damietta and Rosetta estuaries were 7.79 ± 0.04 and 7.95 ± 0.08, respectively, the seasonal variation revealed slight value of pH, where highest value was recorded in summer and the lower value in winter. The site variation was slightly marked.The means dissolved oxygen (DO) concentrations in Damietta and Rosetta estuaries were 4.63 ± 0.18 and 7.47 ± 0.25 mg/l, respectively. The highest concentrations were recorded in winter and summer, while the lowest one appeared in autumn. Site 5 recorded lower dissolved oxygen concentration, while sites 1 and 2 showed the highest dissolved oxygen. The average biochemical oxygen demand (BOD) concentrations in Damietta and Rosetta estuaries were 2.6 ± 0.22 and 2.34 ± 0.16 mg/l, respectively. Sites and seasonal variations manifested a relatively quite variation in BOD mean values.The means of total dissolved solids (TDS) concentrations in Damietta and Rosetta estuaries were 19365 ± 2018 and 4343 ± 580 mg/l, respectively. The highest value of TDS was recorded at site 1, while the lowest one was recorded at site 4. The seasonal variations showed highest concentration of TDS in summer, while the lower values were recorded in spring and autumn. The mean values of total hardness, calcium hardness and magnesium hardness concentrations in Damietta and Rosetta estuaries were 4411.69 ± 358, 664 ± 67.1 & 3747.68 ± 299 and 1206.1 ± 167.4, 315.2 ± 38.5 & 890.8 ±175.1 mg/l, respectively. Summer and winter indicated higher values than those recorded in spring and autumn. The highest value of total hardness, calcium hardness and magnesium hardness were recorded at site 1, while the lowest value was recorded at site 5. The average sulfate concentrations in Damietta and Rosetta estuaries were 1363.7 ± 151 and 289.2 ± 57.2 mg/l, respectively. Summer and winter indicated higher sulfate values than in spring and autumn. Site 1 showed the highest value but sites 3 and 5 recorded the lowest concentrations.The average ammonia concentrations in Damietta and Rosetta estuaries were 0.485 ± 0.059 and 0.131 ± 0.022 mg/l, respectively. The highest ammonia concentration was recorded in summer, while the lowest values were recorded in spring and winter. The site variations were slighting marked. The means nitrate concentrations in Damietta and Rosetta estuaries were 3.25 ± 0.46 and 0.935 ± 0.1 mg/l, respectively. The maximum value of nitrate concentration was recorded in summer and the lowest one was recorded in spring.
The average value of orthophosphate and total phosphorus concentrations in Damietta and Rosetta estuaries were 0.131 ± 0.011 & 0.235 ± 0.017 and 0.245 ± 0.035 & 0.331 ± 0.03 mg/l, respectively. Spring recorded lower values of orthophosphate and total phosphorus than other season. The highest values were recorded at sites 1 and 3.
The averages of total phosphorus concentrations in sediment in Damietta and Rosetta estuaries were 158 ± 6.12 and 162 ± 8.887 mg/kg dry weight, respectively. The minimum value of phosphorus in sediment was recorded in spring. The mean values of total organic carbon (TOC) in sediment in Damietta and Rosetta estuaries were 16.86 ± 1.9 and 12.45 ± 0.73 mg/kg dry weight, respectively, the maximum value of TOC was recorded in autumn, while the minimum value was recorded in summer. On the other hand, the maximum values of TOC were recorded at sites 5 and 4, respectively and the minimum values were recorded at sites 1 and 2. Analysis of variance for the physico-chemical parameters deduced that high significant difference between (one way) sites, seasons and (two ways) sites x seasons (P < 0.05).
Heavy metals concentrations in water of River Nile estuaries showed that, the average concentrations of Cu, Zn, Pb and Fe in Damietta and Rosetta estuaries were 0.167 ± 0.01, 0.158 ± 0.007, 0.022 ± 0.002 & 0.17 ± 0.04 and 0.15 ± 0.007, 0.103 ± 0.014, 0.0128 ± 0.0006 & 0.10 ± 0.018 mg/l, respectively. The values of heavy metals in Rosetta estuary were lower than that recorded in Damietta estuary. The highest concentrations of Cu were recorded in summer and winter, while the lowest one was recorded in autumn. Also, the highest Zn concentrations were recorded in autumn and winter, while the lowest one was recorded in spring. Spring showed high values of Pb, while the lowest one was recorded in winter. The highest concentration of Fe was recorded in autumn, while the lowest value was recorded in summer. The maximum values of Cu, Zn, Pb and Fe were recorded at site 1 and the lowest values were observed at sites 4 and 5 except Fe, which showed high value.
Heavy metals concentrations in sediment of River Nile estuaries showed that, the average concentrations of Cu, Zn, Pb and Fe in Damietta and Rosetta estuaries were 3.59 ± 0.28, 9.85 ± 0.77, 4.59 ± 0.41 & 17.93 ± 0.31 and 2.38 ± 0.2, 4.56 ± 0.44, 4.15 ± 0.31 & 18.15 ± 0.55 µg/g dry weight, respectively. The concentration abundance follows a sequence of Fe, Zn, Pb and Cu. The minimum concentrations of Cu, Zn, Pb and Fe were recorded in autumn. On the other hand, the maximum values of heavy metals were recorded at site 1, while the lowest value was recorded at site 5. The analysis of variance of heavy metals of water and sediment at River Nile estuaries, one way and two ways ANOVA revealed highly significant (P < 0.05).
The average values of heavy metals of Cu in organs (muscle, liver and gills) of Tilapia zillii at River Nile in Damietta and Rosetta estuaries were 2.35 ± 0.04, 10.68 ± 0.56 & 3.44 ± 0.15 and 1.33 ± 0.05, 6.88 ± 0.45 & 2.5 ± 0.06 µg/g wet weight. The highest mean values were recorded in autumn and site 1.
The average values of heavy metals of Zn in organs (muscle, liver and gills) of Tilapia zillii at River Nile in Damietta and Rosetta estuaries were 27.9 ± 2.48, 32.1 ± 2.27 & 35.89 ± 3.54 and 17.57 ± 1.77, 21.8 ± 1.54 & 23.23 ± 1.69 µg/g wet weight. The highest mean values were recorded in autumn and the lowest values were recorded in summer. Site 3 recorded the highest concentration and the lowest concentration was recorded at site 2.
The average values of heavy metals of Pb in organs (muscle, liver and gills) of Tilapia zillii at River Nile in Damietta and Rosetta estuaries were 1.59 ± 0.03, 2.12 ± 0.08 & 2.16 ± 0.11 and 1.29 ± 0.05, 1.74 ± 0.06 & 1.89 ± 0.05 µg/g wet weight. The highest mean values were recorded in autumn and the lowest values were recorded in summer. Site variations of lead were slight.
The average values of heavy metals of Fe in organs (muscle, liver and gills) of Tilapia zillii at River Nile in Damietta and Rosetta estuaries were 26.14 ± 1.7, 36.17 ± 1.14 & 47.23 ± 2.36 and 18.77 ± 1.02, 30.35 ± 3.5 & 35.68 ± 3.94 µg/g wet weight. The highest mean values were recorded in autumn and the lowest values were recorded in summer. Site 1 recorded the highest concentration and the lowest concentration was recorded at site 5 and 2, respectively.
One way, two ways and three ways ANOVA for Tilapia zillii (Table 42) indicated that heavy metals concentrations showed significant differences within sites, seasons and organs (P < 0.05). The concentration of heavy metals in Tilapia zillii during the present study lied in the following sequence: gills > liver > muscles, while the concentration of copper following sequence: liver > gills > muscles.
The average values of heavy metals of Cu in organs (muscle, liver and gills) of Liza ramada at River Nile in Damietta and Rosetta estuaries were 2.11 ± 0.2, 3.45 ± 0.32 & 2.8 ± 0.27 and 1.53 ± 0.09, 3.12 ± 0.06 & 1.99 ± 0.08 µg/g wet weight. The highest mean values were recorded in autumn and site 1, while the lowest values were recorded in summer.
The average values of heavy metals of Zn in organs (muscle, liver and gills) of Liza ramada at River Nile in Damietta and Rosetta estuaries were 14.5 ± 1.33, 29.3 ± 2.53 & 20.9 ± 1.14 and 7.5 ± 0.65, 18.9 ± 1.29 & 15.0 ± 0.79 µg/g wet weight. The highest mean values were recorded in autumn and the lowest values were recorded in summer. Site 1 recorded the highest concentration and the lowest concentration was recorded at site 2
The average values of heavy metals of Pb in organs (muscle, liver and gills) of Liza ramada at River Nile in Damietta and Rosetta estuaries were 1.5 ± 0.07, 2.78 ± 0.18 & 2.73 ± 0.14 and 1.4 ± 0.04, 2.11 ± 0.1 & 1.87 ± 0.05 µg/g wet weight. The highest mean values were recorded in summer and the lowest values were recorded in autumn. Site 3 recorded the highest concentration and the lowest concentration was recorded at site 2.
The average values of heavy metals of Fe in organs (muscle, liver and gills) of Liza ramada at River Nile in Damietta and Rosetta estuaries were 15.3 ± 1.04, 53.5 ± 5.91 & 23.7 ± 2.77 and 11.7 ± 0.41, 25.9 ± 1.47 & 16.7 ± 0.8 µg/g wet weight. The highest mean values were recorded in summer and the lowest values were recorded in autumn. Site 1 recorded the highest concentration and the lowest concentration was recorded at site 5 and 2, respectively.
One way, two ways and three ways ANOVA for Liza ramada (Table 43) revealed that zinc and iron concentration was significant (P < 0.05). For Liza ramada, two ways and three ways ANOVA (Table 43) revealed that copper and lead concentrations were significant (P < 0.05) between sites, seasons and organs, while one way ANOVA of copper and lead concentrations differences were significant between seasons and organs (P < 0.05) and not significant between site (P > 0.05). The concentration of heavy metals in Liza ramada during the present study lied in the following sequence: liver > gills > muscles.
According to the world permissible level of heavy metals in the aquatic organisms showed that The maximum allowable limits of heavy metals in fish organs should be less than the following values: (Cu: 3.6 µg/g wet weight, Zn: 17 µg/g wet weight and Pb: 0.05 µg/g wet weight). Heavy metals concentrations in organs of Tilapia zillii and Liza ramada are over the allowable limits. The present results showed that Pb concentrations in the muscles of the studied fish were higher than the permissible limits, where this values is considered a risk for human health. The concentration of other metals in muscles of fish lied within the allowable limits. The muscle is the important organ of fish, where it is used for food consumption. However, the last values of pollution in Damietta and Rosetta estuaries needs more control and management to reduce the risk of pollution especially at Damietta estuary. from the above results it could be inferred that the concentration of the studied heavy metals in fish organs are in the sequence of Fe > Zn > Cu > Pb. The present study indicated that Damietta estuary is more polluted than Rosettta estuary. However, monitoring programs should continue in order to control and maintain the quality of the River Nile environment. Also we should stop discharging any wastes into the River Nile.