Study of the Heavy Metals Concentration Level in the Water and Sediment and some Tissues of the Grass Carp Ctenopharyngodon idella V. Cultured in Cages in the Euphrates River

Abstract

The current study was conducted in Thi Qar Governorate, Nasiriyah city on one of the private farms, grass carp were cultured, to determine the effect of some heavy elements (cadmium, copper and zinc) in the water and sediments of the Euphrates River, measuring the concentration of elements in some parts (gills, muscles and viscera) of grass carp fish. Water, sediment and fish samples were collected monthly from 11/8/2022 to 4/8/2023. The study also included field tests such as air and water temperature measurements, the air temperature ranged between 11-29 C, and the water temperature ranged between 9-25 C. Heavy metals were measured in water, sediment and fish tissues by flame atomic absorption spectrometer. The results showed the highest total concentration of cadmium in the water during April and copper in February and April, as for zinc, it recorded the highest concentration during April. The highest concentration of cadmium was recorded in the gills and muscles during April. The highest concentration of cadmium in the guts was recorded in the winter. Copper had the highest concentration in the gills and muscles during April. Zinc recorded high concentrations in the viscera, muscles and gills. As for the sediments, the values of cadmium ranged from 0.104-0.223 μg/L. Copper recorded values ranging between 5.07-13.2 μg/L. Zinc values ranged between 29.87-59.2 μg/L. The results showed that the accumulation of heavy elements was as follows: Concentrations in the water of zinc>cadmium>copper. Concentrations in the sediments of zinc> copper>cadmium. In tissues: Cadmium viscera>gills>muscle. gillscopper>viscera>muscles. Viscera>gills>muscles.