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Abstract SUMMARY CHAPTER VI SUMMARY The present study has been focused on the study of water pollution and its effect on hematological, biochemical and histological changes of the two selected fresh water fish (Tilapia zilltt and Clarias gariepinus) caught from two selected regions named EI-Kanater. and El-Rahawy. There are two important sources of pollution which potentially affect and deteriorate the water quality of Rosetta branch. The first source is Kafr EL~Zayat industrial area and the second- source is EI~Rahawy drain” (the region of the present study) which discharge more than . 400.000m3 of domestic wastes in the above mentioned branch, which can destroy the fish health in this region.This drain is few kilometers from Delta Barrage and its wastes are mixture of agricultural, domestic and sanitary drainage from a long ~ea of greater Cairo. Six stations were selected along the delta barrage for water samples collection. The first three stations at Bl-Kanater region, are Damietta branch, in addition to El-Towfeky and Bl-Menoufy sub~branches. While the second, three stations at El-Rahawy region are, Rosetta branch, EIRahawy drain and after El-Rahawy drain. The water sample were collected monthly during March 1997 till February1998 from surface and over bottom layers. Fish samples were collected seasonally during the time of water sampling from EI-Kanater and El-Rahawy regions respectively. (A) Water quality (a):physical characteristics: (1)- Air and water temperature:: Air temperature recorded clear changes at the studied areas, it recorded a maximum value during July 36°C at EI-Towfeky station and a 209 CHAPTER VI SUMMARY minimum one during February 17Cat EI-Menoufy station. These changes are related to seasonal variations of winter and summer. Water temperature follows more or less the changes of air temperature and almost less than air temperature. Some exception were observed where water temperature was higher than air temperature, due to more turbidity of water. They were ranged between 16°C during January at Bl- Menoufy station and 31.4 °c during August at- Damletta station for surface water layer. While/for over bottom layer the values ranged from 160C during December and Japuary at Menoufy and Damietta, respectively to 30.5 °c during August at Menoufy station. No thermal stratification was observed due to its .shallowness and wind action. (2) - Transparency: Its value recorded wide fluctuation between 10cm at El-Rahawy station during June and 11Scm at Rosetta station during December. The higher values occurred in winter while the lower values were observed during summer. There is a distinct correlation between turbidity, temperature and oxygen content. The transparency values depend. on phytoplankton flourishing and water tube. The turbid water seems to be warm and has less oxygen concentration. (b):Chemical Characteristics: (1)- pH Value: The pH values showed a wide range between 6.28 for surface layer and 6.44 for over bottom layer during April at El-Rahawy station i.e. slight acidic and near neutrality and 8.45 for surface and 8.44 for over bottom water during September at Rosetta station Le. the alkaline case almostly restricted. This change related to phytoplankton activity, the high oxygen content and sewage disposal. Lower pH values were L i ; • 210 SUMMARY , CHAPTER VI iiR F (i * observed during Summer months of high temperature leading to the bacterial activity in decomposition of organic matter. (2) Chlorosity : Chlorosity variations proved to be related to the introduction of drainage water, flood and drought periods. Chlorosity showed the highest value of 130.46 mgl’” in December at EI-Rahawy in surface layer and 141.8 mgl ” for over bottom layer as expected during drought period. While the lowest values observed were 15)59 mgt” during June at Rosetta station for surface layer and 17.02 mg.I” for over bottom layer in April at after drain station, as expected during flood period. (3)- Alkalinity: The carbonate alkalinity values were ranged from 0.0 mgl ” during many months and many station to 14 mgt” at El-Rahawy station during March for surface layer. While for over bottom layer the values were ranged between O.Omg1-’ at many stations all year round and 12 mg1-’ at EI-Rahawy station during March. The lowest value of bicatbonate 80 mgt” CaCOJ was detected at EI-Towfeky during January and February, Damietta during February and December and Rosetta during January for surface layer and at Damietta during December for over bottom layer. While the highest values of bicarbonate 352mglo·CaCO) at surface and 344 mgf” CaC03 at bottom were determined during April at Bl-Rahawy. (4)- Oxygen Studies: (4-1): Dissolved Oxygen: El.Rahawy station showed depletion in oxygen content ofO.Omgl-· all the year round for both surface and bottom layers due \0 oXYlen exhaustion in oxidizing the organic matter. But the highest values were 15.2mgl”1 (196.130/0) at surface and 13)6mgl-’ (178.01%) at bottom 211 SUMMARV CHAPTER VI during May at Damietta station because of increasing phytoplankton flourishing, water motion rich in nutrient salts. (4-2) Biological Oxygen Demand (BOD):- The BOD values were increased by increasing the COD values. Its value is widely measured of polluting capacity of an effluent. BOD tend to decrease towards bottom at all stations. The values of BOD were recorded to be between the lower value 1.2 mg l ” at Rosetta during February and the higher value 15.1 mg l ” at EI.Rahawy during December at surface water layer. While for over bottom water layer the values ranged from····theminimum value of2.0 mgl’” at Damietta during February to the maximum value of 19.3mgr’ at El-Rahawy during January for bottom layer. The BOD values were correlated to the higher values of the dissolved oxygen and its exhaustion of organic matter. (4-3) Chemical Oxygen Demand (COD): COD values are higher than DO and BOD due to the amount of organic matter and others in sewage water. So COD is used to assess the degree of pollution. The maximum values of 29.2mgl-1were record.ed at El-Rahawy for surface during December and for over bottom ’water layer was 27.6 mg l” during February. While the minimum values were 4.2 mgl ” at surface during January and October at Rosetta and Damietta , respectively and 1.6 mg 1.1 during January at Damietta for over bottom water layer. The higher COD values at El-Rahawy may be due to the oxidation of organic matter. S..Nutrlent Salts: (5-1) Ammonia: 4. 212 SUMMARY CHAPTER VI Ii ,PI. 4 i j The lower values of ammonia were recorded at Rosetta during January for surface 0.52 mgl·l, and bottom layer 0.27 mgl ” .While the maximum values were recorded at EI·Rahawy during March( 25.64 mg!” for surface water) and the value of25.38 mgl ” for bottom layer in July. Ammonia represented high values at all stations especially at EI·Rahawy. This is attributed to the presence of vari0’:l~ kinds of wastes with high quantities at the studied stations, in addition to drainage water disposal, organic and inorganic fertilizers. (5-2) Nitrite> ’The nitrite values were ranged from I.Slllgl-1 during March at Damietta to 83.87 J.Lgl·l during June at El·RahaWy for surface water layer. While for over bottom water layer the values ranged between l.S8J.LgI-1during March at Damietta and 98.45).1gl·’ during may at El- Rahawy. The higher values of nitrite are attributed to either the reduction of nitrate to nitrite or the oxidation of ammonia to nitrite. (5-3) Nitrate: The lowest values of nitrate were recorded at Damietta station during March for surface were 4.92 IJ.gI-1 and during December and January for bottom 11.11 J,lgl-l• While the highest values were recorded at El-Rahawy station during April for surface were 128.01J.1gr’ and 153.37 ug l” 1 observed at over bottom layer. The high Nitrate values are mainly due to drainage water enriched with nitrate fertilizers and decomposition of dead algae. 5):Hematological Studies: The present· study revealed that the levels of hematological paramotor, for both .elected Ipeol.. cauaht tram Bl-I(anater (lOll polluted area) are found to be lower than those caught from BL·Ri’lawy region (sever polluted area). 21~ CHAPTER VI SUMMARY I-Total serum Glucose (T.S.G): In general,T.S.G level value of Tilapia ztlli! was lower than that recorded for Clarias gariepinus .. The T.S.G levels for Tilapia zillii·· were ranged between 53.29 ± 7.58 mg/l00ml during winter at EI-Kanater and 109.02 ::1:11.08mg/l00ml during winter at EL-Rahawy. -’. For Clarias gariepinus these levels are found’ to be in the range from 96.82 ± 22.74 mg/100ml during autumn at El-Kanater and 163.43 ± 21.94 mg/l00 ml during winter at Bl-Rahawy region. Increase in T.S.G was found to be accompanied by an increase in ammonia and depletion in oxygen. 2-Totnl serum Protein (TSP): The levels of TSP for Tilapia zULUwere found to be in the range from 3.76 ± 0.99 gm/lOOmi during summer at EI-Kanater and 5.95::i::0.98 gm/lOO ml during winter at El-Rahawy, while for C 98Yi’fil1t1J are in the range from 5.65 ± 0.95 gm/IOO ml during Winter at EI-Kanater to 7.66 ± 1.11 gm/l00ml during summer at El-Rahawy. The increase in T.S.P may be due to oxygen depletion occur; an increase in ammonia and damage in both liver and gills. 3-Total Serum Albumin (TSA): Concerning, Tilapia ztllii, the TSA levels are in the range from 1.35 ± 0.58 gm/IOOml during spring for fish caught from EI-Kanater to 2.57 ± 0.78 gmI100ml during winter for fish caught from EI-Rahawy. While for Clarias gariepinus these levels ranged from 1.87 ::I: 0.53 gm/l OOml during winter for fish caught from EI-Kanater to 3.25 ± 0.91 gmllOOml during summer for fish caught from El-Rahawy. These also reflect the effect of stress pollution on fish caught from polluted area. 214 SUMMARY CHAPTER VI • 4-Total Serum Globulin (T.S.Gl): The values ofT.S.Ol of Tilapia zillii were recorded the minimum value of 3.32 :i: 0.74 gmllOOmland the maximum value of3.66:1: 0.74 gmllOOml at EI-Rah~WY during summer and autumn seasons, respectively. While for Clarias gariepinus the T.S.Gl values ranged from 2.49:i: 0.53 gmllOOml during winter for fish caught from El-Kanater to 5.03 ± 53gm/lOOmlduring autumn for fish caught from El-Rahawy. Increase in albumin and globulin may be due to increase in metabolic rate of albumin and globulin due to lack of oxygen. C: ~iochemical studies: The main biochemical constitijents were studied in fish flesh of Tilapta zillit and Clarias gariepinus caught from ~l-Kanater region and EI-Rahawy drain. The obtained results revealed the followings. I-Water content: The maximum value obtained for Tilapia .zUIU caught from El- Rahawy drain during summer season, was 84.98 0/0,while for Clarias gartepinus the maximum value was 84.68 % for those caught from EIKanater region during spring season. The minimum value obtained for Tilapia zillii caught” from Bl- Kanater region during spring season was 76.870/0,while for Clarias gariepinus the minimum value was 76.32% for those caught form El- Rahawy drain during winter season. It is to be noted that the water content.were higher for immature fish than that of mature fish. 2-Protein Contents. The maximum value of the protein content in fish flesh of Tilapia zillii was recorded during spring season at EI-Kanater region being 215 SUMMARV CHAPTER VI =84.00%, while the maximum value ofC/arias gariepinw was recorded during autumn season at EI-Kanater region being 84.250/0. The minimum value of the protein content in fish flesh of Tilapia zil/ii was recorded during summer season at BI-RahaWYregion being 78.17% while for Clarias garieplnw the minimum one was recorded during spring season at Bl-RahaWYdrain being 67.46 % The protein content showed a lower value towards matuation. 3-Lipid Content: The maximum value of lipid content for Tilapia zULUwas recorded during autumn season at EI-RahaWYdrain being 18.110/0,while for Ciarias gariepinw was recorded during winter season at El-Rahawy drain (being 19.040/0) . The minimum value of lipid content for TUapia zULUwas recorded during spring season at El.Kanaterregion, being 8.92%, while for C/arias garieplnus the minimum one was recorded during autumn season at ~I· Kanater region, being 9.73%.The values of lipid content increase by increasing maturation. 4-Ash Content: The present results showed that the higher values of ash were obtained during autumn season in fish caught from El-Kanater region for Tilapia zil/ii and Clarias garieplnw being 8.80% and 7.42% respectively. While the lower values of ash for Tilapia zil/il caught from El-Kanater was recorded ( 4.67% ) during winter season , and that ( 4.31% ) for C/arias garleplnw caught from EI-Rahawy drain was observed during the same season. S_Carbobydrate Content: The maximum value of carbohydrate content in fish flesh of Tilapia zillii obtained from EI·}(anater region during autumn season, 216 CHAPTER VI SUMMARY .n being 2.47%, while for Clarias gariepinus the maximum value was recorded at El-Rahawy drain during spring season, being 2.21 %. The minimum value of carbohydrate content for TUapia ztlli! ’recorded at El-Kanater region during autumn season, being O.04%,while was O.05%for C.,,’Yit.piIJ”J at the same region, during summer season. The change in carbohydrate not related to sex, season or region and are not affected by pollution. As a general the present results indicate that: • Water content showed seasonal variations to a’ great extent, and an inverse relationship was exist between water and lipid ’contents, so summation of both constituents were approximately constant. • The two selected fish species showed a decrease in protein content of fish at EI~Rahawy, due to the effect of pollution stress. • Lipid content was higher for the two species caught from EI-Rahawy than those from El-Kanater. It was observed that, the lipid content of CooJ3ril;ei;7V5 was higher than that of Tilapla zi/lii at two regions. • Finally, there was an inverse relationship between ash and water content as the ash content decrease according to the stress of pollution. Generally, the coefficient of variations showed that, the carbohydrate content have the highest value, however the protein content showed the lowest one. Also, these values in Clarias gariepinus caught from El-Rahawy drain showed great variations than those caught from EJKanater (less pollution area). D.HI.ioloa1ca1 Siudt, ••- Gonads (ovaries and testes), liver, gills and muscles samples were obtained from the two selected fish Tilapia zUlii and Clarias gariepinus caught from the two investigated areas (El~Kanater and EI~Rahawy). 211 CHAPTER VI SUMMARY I-Gonadsr a)Tes.tes: The morphological study of testes showed that, some sample appear to be dark in color especially those obtained from El-Rahawy for the two selected fish. The histological study .showed separation, destruction and sometimes absence of testes wall. Also destruction in seminiferous lobule wall, cyst wall, spermatocytes and connective tissue. Appearance of necrotic area with accumulation of hemosldrln in some tissue. Activation of spermatid occur. Hemorrhage, hemolysis and hemosidrin in blood vessel with thickness, anastomosis (branching) and fibrosis of its wall. These alteration was ascribed on the increase in ammonia and other pollution, in addition to spawning season. b) Ovary: Morphologically, ovary ·sometimes appear dark in color. The histological examination of ovary revealed destruction of ovarian wall. Necrosis, destruction and accumulation of hemosidrin in connective tissue between ova. Dilation, congestion, hemorrhage, hemolysis, and thickness in blood vessel. Separation of yolk from ova wall or ova nucleus in some specimens. Hyperplasia of granulosa lead to fusion of ova, sometimes granulose invade part of ova or cover all ova and this leads to ova destruction, separation of theca from granulosa and also absence of part of zona radiata, Some nuclei appear to be empty. These malformations may be due to increase in ammonia and nitrite,in addition to spawning season. 2) Liver: Morphologically pale red or dark blue color were observed in the liver obtained from fish especially these caught from El-Rahawy drain. Also some specimens were enlarged in size. ?lR CHAPTER VI SUMMARY Microscopically, . a qestruction, necrosis, fatty degeneration, hemorrhage and hemolysis of hepatic cells are ’shown ; congestion of blood slnusolds; dilation, hemolysis, edama, destruction and thickness of• blood vessels. In addition to stagnant of red blood cells in blood vessel. Anastomosis (branching) and fibrosis of bleed- vessel. The above mentioned malformation of liver were sever for the two studied species which caught from EJ. Rahawy region. tl’he liver damage can be attributed to oxygen depletion’,parasitc, increase of ammonia,. virus and bacteria in polluted water. 3) Gills: Morphologically, the specimens offish obtained from El·Rahawy region appear-to be dark in color and covered with mucin. The histological studies of the gills of the two selected fish . especially which caught from EI·Rahawy region. These changes were . . hyperplasia of epithelial cells of primary and secondary lamellae which ’.. lead’ to fusion of lamellae; nodular proliferation of two lamellae; curling and bump of tips of secondary lamellae, in addition to separation and degeneration of epithelial cells of it. Parasitic cells appear for two selected fish caught from two regions’. Dilation, hemorrhage, hemolysis of blood vessel was observed; also destruction edema, hemorrhage, hemolysis and some hemosidrin in primary lamellae. The gill changes may be due to increase of ammonia ,pH changes, oxygen depletionJ bacteria, micro~organisms, parasites,and turbidity. 4) Sldn and Muscles The skin of Clarias gartpinus obtained from EI~Rahawyregion appeared with white spots and destroyed dorsal fin. 4 ·119 SUMMARV CHAPTER VI 5i* . ’. The histological study of skin and muscles of fish showed that there were fibrosis and absence of epithelial cells. Hyperplasia, hypertrophy, necrosis, ’degeneration, destruction and hemosidrin in mucous cells (epidermis). Destruction, degeneration of collagen bundle (dermis layer). Necrosis, hemolysis and hemosidrin in connective tissue(hypoderm). Edema, Lecamea, destruction, hemorrhage, hemosidrin necrosis and appearance of abnormal shape in muscle fibers layer. The above mentioned malformation of muscles appeal’ greatly for Clarias gariplnus obtained from two region than the other selected fish at the same region. These malformation of skin and muscles, which means that Tilapta zi/l tt is more resistant towards pollution than Clarias gari epiAUJ. |