Study of the Physical and Chemical Properties and Accumulation of Heavy Elements in the Fishes and Water of the Tigris and the Lower Zab Rivers in Iraq

Estimation and Measurement of some physical and chemical properties and heavy elements of the water and fishes of Tigris and Lower Zab rivers in Iraq. A Cross-Sectional Analytical Study (field sampling with repeated measures). The study was carried out during the period between September 2024 and February 2025 in four stations. The samples were collected from the area of confluence of the lower Zab River with the Tigris River and the areas near it using polyethylene pots with a size of 2.25L to measure some physical and chemical properties. The averages of the values of turbidity, pH, nitrates, phosphates, total Alkalinity and potassium ranged between (57.183-72.585), (7.7983 - 7.9683), (1.35083- 1.8193), (1.2563-1.8263), (85.64016- 94.8045), (1.353 -1.4801) respectively As for heavy elements, copper, zinc, lead and iron were measured in water, and the results of the average values of copper, lead and iron in water were between, (0.115783 - 0.1587906) , (0.08913 - 0.1476) , (0.0511-0.1230) , (0.0906 -0.1463) respectively In the fish, four types of fish were collected, namely golden sea bass, Common carp, Grey Mullet and Iraqi Shilag fish, and their average sizes ranged between (13.2325- 65.7475 ) cm and their average weight between (115.4000-1357.1250) g and heavy elements in fish, the average values of copper, zinc, lead and iron ranged between (0.0161 - 0.0283). (0.1063 -0.1735), (0.0044 - 0.070), (0.1171 - 0.1715) respectively. Inconclusion the proportions of physical and chemical properties and heavy elements were differed according to the difference in temperature and the rainfall rates, as well as the impact of the lower Zab River on the Tigris River in that region, which flows into it, so the heavy elements reach fish through the food chain, as heavy elements move from water to phytoplankton. So, the fish and water have a comparable heavy elements ratio.