Seasonal variations of heavy metals concentrations in mullet, Mugil cephalus and Liza ramada (Mugilidae) from Lake Manzala , Egypt

Abstract

easonal variations in the concentrations of four heavy metals; zinc (Zn), copper (Cu), lead (Pb) and cadmium (Cd), were determined in gills, skin and muscles of two fish species (Mugil cephalus and Liza ramada) from five locations in Lake Manzala. The average concentrations of the metals in fish tissues exhibited the following order: Zn>Cu>Pb>Cd. The statistical analysis revealed a significant effect of seasons, locations and fish tissues for all metals measured. The highest values of the metals were recorded in hot seasons (summer and spring). Fish samples from location V (Bahr El-Bakar) displayed the highest metal concentrations in their tissues. The highest concentrations of heavy metals were found in gills tissue of both fish species, while the lowest ones were recorded in muscles tissue. The values of the metals detected in the edible fish muscles were within the permissible limits.

Physicochemical properties of Manzala Lake, Egypt

“…Fortunately, pollutants usually concentrate in the liver, kidney or gill tissue of fish species and not to the same extent in the body muscles that make it safe food if these organs are discarded [13,14]. However, continuous assessment of water quality parameters is necessary to monitor and understand the effect of different water resources on water quality of Manzala Lake.…”

Copper, Lead and Zinc Concentration in Water, Sediments and Catfish (Clarias macrocephalus Gunther) from Butuanon River, Metro Cebu, Philippines

“…However no significant difference across the sampling stations were noted although a slight increase is observed downstream possibly caused by four galvanized iron facilities where zinc is used as a coating to prevent corrosion [31]. Additional sources could be through the settlement of Zn metal transported by the water [34]. Overall, results of this study indicate that Zn is a natural component in the sediment of Butuanon River since it is fairly abundant upstream at 96.157 ppm despite the absence of identified source in the area.…”

“…It should be pointed out that the liver of the fish plays a primary role in the metabolism and excretion of xenobiotic compounds with morphological alterations occurring in some toxic conditions [33]. The concentration of these metals in the gill tissues of catfish (C. macrocephalus) could possibly be related to the fact that they are the main sites for pollutant uptake due to the large surface that is in contact with environment and the very thin barrier separating the external and internal media of the animal [34]. On the other hand, the muscles of the catfish having contained the lowest levels of heavy metals could be due to being an inactive site in accumulating metals [35].…”

Impact of Genotoxic Contaminants on DNA Integrity of Copepod from Freshwater Bodies in Chennai, Tamil Nadu, India

“…Fe is an important metal in both plants and animals particularly in the cellular process [18]. The insoluble Fe 3+ is reduced to soluble Fe 2+ in water by bacterial reduction.…”