EVALUATION OF SEASONAL CHANGES OF HEAVY METAL ACCUMULATION IN WATER AND ORGANS/TISSUES OF SOME FISH SPECIES INHABITING LAKE MANZALA, EGYPT.
Islam M. El-Manawy1*; Ibrahiem M. Shaker2;
Mona H. Ahmed 2 and Mohamed M. Salama2
1 Botany department, Faculty of Science, Suez Canal University, Egypt.
2Central Laboratory for Aquaculture Research (CLAR), abbassa, Abou-Hammad, Sharkia, Egypt.
* Correspondent author: email: [email protected]
| Received 14/ 11/ 2019 |
Accepted 15/ 12/ 2019 |
Abstract
Fe, Mn, Zn, Cu, Pb, and Cd concentrations in water and tissues of some fish species namely; tilapia species, mullet (Liza aurata) and catfish (Clarias gariepinus) inhibiting lake Manzala were determined seasonally during July, 2016 to June, 2017. Metals in water and fish tissues show a significant (P< 0.05) seasonal and regional variations, in which the maximum values of all metals were observed during summer, while the lowest levels were found during winter. The concentration of the measured heavy metals were found in the following order Fe > Cu > Zn > Mn > Pb > Cd. The highest concentration of Fe (1.60 mg/l), Cu (0.77 mg/l), Zn (0.67 mg/l), Mn (0.58 mg/l), Pb (0.319 mg/l) and Cd (0.196 mg/l) were recorded at the southern part of the lake (Region 3). Also, heavy metal concentrations varied significantly (P< 0.05) depending on the type of the tissue and fish species as the higher concentrations were recorded in liver and gills than muscles. Generally, the heavy metal levels in fish tissues of different fish species were found in the order: Clarias gariepinus > Liza aurata > Tilapia
species. High concentration of Fe (1792.33 μg/g dry wt.), Zn (80.96 μg/g dry wt.), Mn (49.66 μg/g dry wt.), Cu (85.03 μg/g dry wt.), Pb (3.96 μg/g dry wt.) and Cd (4.61μg/g dry wt.) were recorded in liver of catfish collected from the south part of the lake (Region3), while muscle tissues retained the lowest in all types of fish.
Keywords: Water; Heavy metals; Lake Manzala; Fish; Tilapia; Clarias gariepinus, Liver, Muscles
