دراسة بيئية مقارنة لتاثير الحاجز المائي في قضاء المدينة عند اسفل نهر الفرات == A comparative ecological study to the impact of Mudayna district barrier at the lower reaches of Euphrates River
Author name:
سجاد عبد الغني عبد الله
Supervisor name:
صادق علي حسين | عبد العزيز محمود عبد الله
General topic:
Agricultural sciences
Specific topic:
Zoology - Fish And Marine Wealth
Degree:
Master
University:
University Of Basrah - Faculty Of Agriculture - Department Of Fish And Marine Wealth
Language:
Arabic
University location:
Basrah
First pages:
31T1804 - p.pdf
Abstract:
An Ecological study was conducted, on monthly basis, for the period from November 2013 to October 2014, on the Lower reaches of the Euphrates River covering a location at northwest of Basrah province within the area between Al - Chebaysh district of Thi Qar province, and Mudayna district of the city of Basrah. The study area covered a distance of 16 kms lies between latitudes 47˚00 ' 18.81 " and 47˚09 '55.46" E and latitudes 30˚57' 41.53" and 30˚57'7.38" N. On 2010 the Ministry of Water Resources constructed an obstruction on the Euphrates River, 11 km west of Mudayna of a width 760 m. It’s aims is to raise water levels in the western side of the river for water to flow to Hor Al - Chebaych. Three stations were selected to execute the study. The former was situated in front of the Chebaish district and with a distance of nine kilometers east where station 2 was located. However, to the east of the constructed embankment and just three kms apart station 3 was chosen. The study revealed that air temperature ranged from 11 - 45°C and water from 10.5 - 37°C, light penetration from 15 to 210 cm. Turbidity from 0.66 NTU in October at station3 and 40.8 NTU in September at station1. Current speed ranged between 0.01 m/s to 0.41 m/s.The lowest value of Electric conductivity (2.4μS/cm) recorded in November at station 3 and the highest (5.74μS/cm) in March at station 1. Total dissolved solids between 1788 mg/ L to 3832 mg/L. the lowest value of pH (7.4) measured in August at station 2 and the highest (8.7) in February at Station 3. Dissolved oxygen ranged from 5.5 to 10.1 mg/L. BOD5 ranged from 0.19 to 3 mg/L. The lowest value of salinity (1.3 g/L) recorded in June and July from Station 2 and the highest (2.9 g/L) was encountered in February at station 3. Total hardness the lowest (880 mg/L) encountered in July at station2 and the highest (1350 mg/L) in February at station3. Total alkalinity ranged from 84 to 182 mg/L. Reactive nitrate ranged from 0.6 to 37.7μg at. N/L. Reactive phosphate ranged from 0.023 to 1.857μg at. P/L. Concentrations of some heavy metals were also studied. Copper was impalpable in November and December in stations2 and 3, but the highest (1.90 μg/L) was in August at station2. Intangible value was also recorded for Lead in November at station3 and the highest (0.1 μg/L) in July of the same station. Non - tangible value encountered for cadmium in November and December at stations 2 and 3 but the highest (12.73 μg/L) in July for station1. The study took in consideration application of the general index to the quality of water (CCME) as seasonal readings were calculated depending on river maintenance system for the year 1967 and amended in 1980. Throughout the study period values ranged between marginal (56.3) and FairB(69). Values were obtained depending on the previous studies, as were between marginal (47) and Fair( 65). Fish community structure was described. A total of 11851 specimens were collected included 28 species and 25 genera belonging to 12 families all belong to class bony fishes Osteichthyes. Cyprinidae came first concerning the number of species (13) and genera (11) and composing 37.44 %, these are Hamri (Barbus luteus), Prussian carp (Carassius auratus), grass carp (Ctenopharyngodon idella), (Acanthobrama marmid), (Alburnus mossulensis), Shillug (Aspius vorax), bunni (Barbus sharpeyi), gattan (Barbus xanthopterus), Hemicultuer leucisculus), small mouth benine (Cyprinon kais), big mouth benine (Cyprinon macrostomum), (Garra rufa) the mullet family Mugilidae formed 35.50 % and consist two species , namely, Liza abu green and Liza subviridis. Tilapia Cichlid family was represented by 21.84 % and two species, namely Tilapia zilli and Oreochromis aureus. Gumbusia (Pociliidae) formed 2.70% and represented by two species , namely (Gambusia holbrooki) and Poecillia latipinna, Clupeids family accounted for 0.025% and represented by two species, namely Tenualosa ilsha) and Nematalsoa nasus. However one species of seven families included Siluridae (Silurus triostegus) 0.58%, Sparidae Acanthopagrus latus (arabicus) 0.57%, Mastacembelidae (Mastacembelus mastacembelus) 0.28% , Hemiramphidae Hyporhampus limbatus)) 0.23% and minnows Engraulidae (Thryssa whiteheadi) rate of 0.345 % and Gobiidae (Bathygobius fuscus) was collected for the first time in the study area and in station 3 at 0.050 % and Heteropneustidae (Heteropneustes foosilis) formed the lowest contribution. The study also was taken in consideration the diversity indices in the Euphrates. The lowest value (1.04) of Shannon diversity index (H) was recorded in May from station1 and the highest (2.70) in the same month from station3, and was the lowest value for the evenness index (J) (0.476) in May was recorded for the station1 and the highest (0.933) in January. The lowest value of richness index (D) (0.868) was obtained in December from station1 and the highest (3.285) in May from station3. The lowest value for Jaccared similarity index (13.25 %) was in October between stations1 and 2 and the highest (100 %) in November and January between stations 1 and 2. Multivariate analysis (CCA) was applied to clarify the relationship between abiotic environmental characteristics and fish distribution in the aquatic environment.
