Document Type : Original Article
Author
Abstract
The study was completed in Basra Governorate in the central part of Shatt Al-Arab River, and two stations were chosen to carry out the study. The first one is near the island of Sindbad located on the coordinates "N30 ° 34´18.4872", E 47 ° 46´44.9292 ", the next station is proximate the Al-Sadr Educational Hospital within about N30 ° 30´34.6608 ", E74 ° 51´7.2108". Samples were collected on a monthly basis for a period of one year, during the low tide, and for the period from September 2018 until August 2019. Some environmental factors of water were measured as well as (water temperature, pH, dissolved oxygen, biological oxygen demand, light penetration, salinity, total dissolved salts, total hardness, reactive nitrate, reactive nitrite and reactive phosphate). The WQI (Canadian Model) was used for assessment as an efficient method for assessing the water environment and determining its suitability. Zooplankton were collected and diagnosed, both quantitative and qualitatively. The results of the study showed that the temperature ranges ranged between (14-37) ° C, pH values were between (7.1-8.1), Dissolved oxygen (6-11) mg.L-1, the biological oxygen demand was between (0.5-3.5) mg.L-1, the light penetration values were between (22.5-165) cm, salinity ranged between (0.9-15.42) ‰, total dissolved salts between (1646-17158) mg.L-1, total hardness between (4800-480) mg.CaCo3.L-1, reactive nitrate are between (0.02-3.24) μg nitrogen atom. l-1, reactive nitrite values were between (0.02-1.21) μg nitrogen atom.L-1, and reactive phosphate was between (0.01-0.86) μg phosphorous atom. l-1. The water quality index on record the highest value (61.46) in the fourth category Marginal in the summer for the first station, and the lowest value was recorded (33.11) in the fifth group Poor in the winter for the next station. 98 taxa of zooplankton, which recorded in the 1st station, 61 Rotifera, 15 Cladocera, 12 Copepoda, 7 miscellaneous groups and 3 Ostracoda. 79 taxa of zooplankton recorded in the 2nd station, 53 Rotifera, 13 Copepoda, 5 Cladocera, 5 miscellaneous groups and 3 Ostracoda. The maximum total density of zooplankton was 3561.53 and 1532.95 ind.L-1 for the first and second stations respectively. Statistical analysis was applied to make clear the relationship between environmental factors and zooplankton in the aquatic environment
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