The concentration of Some Heavy Metals in the Water, Sediment, and Fish Muscles of Tilapia Fish in Two Different Natural Water Southern Iraq

The concentration of certain heavy metals (Pb, Zn, Cu, Mn, and Cd) was determined in the water, sediments, and tilapia fish (Coptodon zilli, and Oreochromis niloticaus) from the Tigris River and the fish ponds of Marine Science Centre, University of Basrah, Southern Iraq, during the period April-June 2019. Pb and Zn have the highest concentrations (0.51466 mg/100L) in fish ponds and (0.63 mg/100L) in the Tigris River. Heavy metal concentrations were generally higher in sediment samples than in water samples. Zn recorded a high level of heavy metals in fish pond sediments and the Tigris River. Lead (Pb) has been the most abundant heavy metal identified in the fish muscles. It varied from 0.3010 to 0.8560 mg/100 g in the muscles of C. zilli , and O. niloticus in the Tigris River, respectively. Cd, not detected in all samples of fish. The results showed significant differences (P<0.05) in the bioconcentration of metals in the muscles of O. niloticus and C. zilli fish. Pb shows the highest bioconcentration (8.7622 and 4.2016) in the O. niloticus and C. zilli fish muscles respectively in the waters of the Tigris River. Fish can accumulate heavy metals from their environment and act as bioindicators for these metals. Fish can therefore be considered as ideal organisms in the study of certain long-term variations in the heavy metal concentrations in their environments.