المستخلص:
The current the study included and analysis of Diatoms community in the sector of the Tigris River and in the area between Dejail spend in Salahuddin province to the Muthanna Bridge area before entering the river to the city of Baghdad. Six sites have been Chosen along the river to collect samples of water per month for the duration of January until December 2014, physical and chemical factors of water were measurement, also included a study of the quality and quantity of phytoplanktonic diatome epipelic and epiphytic on (Phragmites australis Trin ex Stand ) Diatoms, also addressed the evaluation of the Tigris River water quality in the study area for the purpose of living aquatic - based Canadian Model (Canadian Council of Ministers of Environmental Water Quality Index), in addition to measurement of total concentrations of some heavy metals in water samples and applied pollution - index to evaluated the level of pollution. The results showed the presence of spatial and temporal heterogeneity in rates of physiochemical characteristics of the region studied values , as factors rates ranged as follows : Temperature of the air and water between 11.54 - 38.41c °, 13.43 - 30.36 c°, the depth, light transmittance and turbidity rates were fluctuated in different stations and seasons, as it ranged between 4.25 - 6.83 meters, 38.33 - 76.66 cm 13.03 - 136.76 NUT the flow velocity ranged between 0.50 - 3.37 m/s respectively, as for values of conductivity (EC) , Sodium chloride NaCl , TDS, and salinity increased trend of Muthanna Bridge area , with rates 711 - 1592 ms/cm, 1.5 - 3.5 % , 380.66 - 898.33 mg /L and 0.43 - 0.99 per thousand respectively. Characterized sector water as neutral or alkaline mild in terms of pH , as it ranged between 7.07 - 7.65 , also recorded an increase in dissolved oxygen, DO and bio - oxygen demand, BOD in the winter, and fall gradually in the spring and autumn values , the lower values recorded in the summer and were 2.20 - 9.13 and 0.41 - 3.90 mg / l ,Also the water of study aria Characterized with highly concentrations for Ca compared with Mg and ranged 54.66 - 164.66 and 23.66 - 39.66 mg / L, respectively, while values of Cl and Fl were between 31 - 99 and 0.08 - 0.39mg/L. Water sector characterized as very hardness , amounting to total hardness between 241.66 - 556.66 mg/L, either alkalinity rates ranged values was 86 - 142 mg /L. the result of study prevailed that the values of NO2,NO3,PO4 Affected by various additions to the river hyphen as a remnants of human activity or rainfall , as values ranged between 0.002 - 0.006 mg/L , 0.37 - 1.13 mg/L and 0.19 - 2.51 mg/L, respectively. Also the silicate, SiO3 and Sulphate SO4 recorded high values in all and some stations and ranged 2.84 - 4.74 and 85 - 554 mg/L respectively. The Chlorophyll (a, b and c) of planktonic diatoms recorded clearly fluctuated values in the current study, and arrangement for both (0.02 - 0.30, 0.07 - 1.10 and 0.03 - 3.46 mg/L. also appeared that the chlorophyll values of epipelic diatoms were higher than in planktonic , when recorded for ( a , b , c) 0.35 - 3.85, 0.08 - 1.53 and 0.10 - 3.07 mg /L respectively. In the current study 515 taxa of diatoms were diagnosed, they were distributed among the planktonic, epipelic and epiphytic on (Phragmites australis). Diatoms belonging to 21 families and 55 genus , Including 16 families and 47 genus of pennales and 5 families and 8 genera of centrales. The study was also able to record 29 new species as a new record for Iraqi flora, belong to pennales diatoms, and distributed as a flowing : 7 species (Bacillaria Paradoxa var.tumidula.Grun, Campylodiscus bicostatus W.Smith, Cymbella brehmii Hust, C. hebridica Gregory C. norvegica Grun, Diatoma vulgare var. constricta.Grun,. D. vulgare var. fromes astries abnormale,) planktonic, 4 species Gomphonema intricatum var.vibrio(Ehr.Cl) , Navicula incerta (Nach.Grunow),N. punctata var.punctata W.Smith , Surirrila suecice Grunow) Epipelic, 5 species (Achnanthes exigua var.heterovalva Krasske, Gomphonema subtile, G. tenellum Kutz , Synedra cyclopum Brutschy, S. incisa A.Boyer.) epiphytic on (Phragmites australis), Achnanthes plonensis Hust.4 species Anomoeoneis serians var.apiulata, Denticula thermalis Kutz., Navicula subrhyncocephala Hust., associate between epiphytic and epipelic diatoms, 6 species ,Achnanthes grimmei Krasske., Anomoeoneis vitera Grun., Gomphocymbella ancyli (Cleve)Hust., Navicula capitatoradiata nomen novum., Nitzschia incospicua Grun, distributed among the three environments, 2 species Cocconeis scutellum Ehr. and Navicula rhyncocephala var.germaini, as planktonic and epipelic, and one species Nitzchia obtusa var.multistriata Hohn, associate between planktonic and epipelic diatoms. The qualitative study has shown that 377 taxa of planktonic diatoms belonging to 20 families and 49 genus, which pennales were, dominate by 90.45 % (341species and 42 genus), while the centrales recorded 4.55% with ( 36 species and 7 genus) from the total of planktonic diatoms. The total number of species of planktonic diatoms wandering variation depending on the seasons and the stations, as the St4, recorded the highest number of species (65) in the winter, while the lowest number (17) species was at St1, in the summer. Also Observed heterogeneity in rates of total of individuals of plankton diatoms in different seasons and stations study, as it scored the highest average number 216.36 × 104 cells / L at St4, in the winter , and the lowest 33.62 × 104 cells /L at St2, in autumn. 298 taxa of epipelic diatoms have been diagnosed in this study, belonged to18 families and 45 genus, dominated by pennales with 94.93% (40 genus, 281 species). While the centrals recorded 5.74% (5 genus , 17 species), clearer variations observed in total of numbers for species in different seasons and stations, as recorded the highest numbers 70 species at St5, in winter, so for the St6 and St2, recorded the lowest 18 species in summer and autumn, also the numbers of individuals differenced ,as recorded the highest 91.48 x103celle/cm2 at St3 in autumn, and the lowest 6x 103 cells/cm2 at St6 in summer. The total numbers of species of epiphytic diatoms on P.australis plant reached 333, belonged to 19 families and 45 genus, the pennales recorded the highest percentage, 94.29% (39 genus and 314 species), so for the centrales get 5.71% and (19 species, 6 genus), a variation in numbers of species in different seasons and stations of study observed, as found to outweigh the 3rd St, in number of species in autumn and scored 75 species, while the St2, recorded the lowest number 38 species during the summer. Also appeared variation in the total number of individuals depending on the seasons and stations, as it scored the highest rate of cells 209.4 × 104 cells / g wet weight in the St4, in autumn, and the lowest number 25.41 × 104 cells / g wet weight at St6, during the summer. In this study Adopted four ecological indexes ( richness , diversity, the similarities and differences ) as the results showed that evidence richness and diversity of planktonic diatoms wandering values ranged between 13.58 - 3.93 and 4.05 - 2.67 , The highest value of the similarity 0.261, and the lowest value 0.103, the highest value of the difference 0.957 and the lowest value 0.586. As evidence of the richness and diversity of epipelic diatoms ranged between 19.45 - 6.61, and 3.89 - 2.05, respectively, Also recorded the highest value of the similarity 0.313 and the lowest value 0.086 , so for found the highest value of the difference 0.826, and the lowest value 0.524. While evidence richness and diversity of epiphytic diatoms recorded values ranged 16.89 - 10.44 , and 3.95 - 3.12 , respectively. While the highest value for the similarities 0.420 and the lowest value 0.173 .The highest value of difference 0.742 and the lowest was 0.408 ,when calculating the indices of water quality for the purpose of living aquatic organisms by using 15 factors ( water temperature , turbidity TDS, pH, DO, chloride, NO2 , NO3 , PO4, Fe , Cd, Cu, Pb, Ni and Zn) , the results showed that the quality of water of Tigris River for living aquaculture in area studied area got a (conservative estimate) , as evidence of the highest value 79.64 at St4, in winter and the lowest 65.95 at St1, in summer. The study also included a measurement of the total concentration of some heavy metals in water samples such as iron , cadmium , copper, lead , nickel, zinc , and their values ranged between 0.24 - 1.27 , ND - 0.038 , 0.033 - 0.383, 0.0178 - 0.469, ND - 0.323, 0.020 - 0.231 mg / L, respectively. From results we can concluded that the waters of Tigris River in the study area is contaminated with heavy metals more than the rest of the studied factors , especially regarding cadmium , copper, lead and zinc , and the two stations St3 and St6 were most polluted than the others. When applying heavy metal pollution index , we find evidence that the highest value (100) for the element Cd in all stations while recorded the lowest value ( 0.33 ) for the element Ni.
اسم المشرف:
ابراهيم مهدي عزوز السلمان
اسم المؤلف:
بثينة عبد العزيز حسن المكدمي
