Using O. aureus and C. zillii as Bio Indicators in the Marsh of Dalmaj Southern Iraq

Abstract Due to of ongoing industries, humans cause water pollution and discharge of sewage into the water, which have contributed to the decline in the number of animals in the Dalmaj Marsh, which is home to thousands of species. Metals for instance mercury, cadmium, chromium, and lead pose a significant danger to public health and other animals such as fish, leading to carcinogenicity and renal failure. We can deduce that O. aureus acts as a highly efficient bio-indicator for heavy metals, including Pb, Mg, Cr, and Cd, in comparison to C. zillii. These metals also have impact on water quality and can interact with environmental variables, so in the current study we used procedures approved by the World Health Organization to evaluate concentrations of Lead, cadmium, chromium, and mercury in some fish species namely C. zillii and Oreochromis aureus as vital indicators of environmental pollution and monitoring environmental pollution in general to preserve biodiversity in the marsh of Dalmaj located in Al-Diwaniyah town area/Iraq from the period of August 2023 to January 2024. A difference in the concentrations of heavyweight metals accumulated in fish parts during all months of the study has been indicated, and all metals levels were within the internationally permissible limits. In addition, there was a slight increase in some heavy elements in the two studied types of fish species found in the Dalmaj marsh from one month to another. Our findings provide crucial basic data that reflects the quality of water in the Dalmaj Marsh. We recommend conducting more studies every year to screen heavy metal effluence in the waters of the Marsh of Dalmaj.