The effects of seasonal heavy-metal pollution of Ladik Lake on pike fish (Esox lucius)

Seasonal assessment of selected trace elements in grass carp (Ctenopharyngodon idella) blood and their effects on the biochemistry and oxidative stress markers

Environmental pollution by anthropogenic activity is still a highly relevant global problem. Aquatic animals are a specifically endangered group of organisms due to their continuous direct contact with the contaminated environment. Concentrations of selected trace elements in the grass carp (Ctenopharyngodon idella) (n = 36) blood serum/clot were monitored. Possible effects of the elements on selected biochemical and oxidative markers were evaluated. The concentrations of trace elements (Al, Ba, Be, Bi, Cd, Co, Cr, Cu, Fe, Ga, Mn, Mo, Ni, Pb, Sr, Tl, and Zn) were analysed in the fish blood serum and blood clot by inductively coupled plasma optical emission spectrometry (ICP OES). A general scheme of decreasing concentrations of trace elements in the blood serum samples was: Zn ˃ Fe ˃ Sr ˃ Ba ˃ Ni ˃ Al ˃ Cu ˃ Be ˃ Co; < LOQ (below limit of quantification): Bi, Cd, Cr, Ga, Mn, Mo, Pb, Tl; and in the case of the blood clot, the scheme was as follows: Fe ˃ Zn ˃ Sr ˃ Al ˃ Ni ˃ Ba ˃ Cu ˃ Be ˃ Co ˃ Mn; < LOQ (below limit of quantification): Bi, Cd, Cr, Ga, Mo, Pb, Tl. Significant differences among the seasons were detected. The Spearman R correlation coefficients and linear or non-linear regression were used to evaluate direct relationships between trace elements and selected blood biomarkers. The correlation analysis between biochemical parameters (Na, K, P, Mg, AST, ALT, ALP, GGT, TAG, TP, urea, glucose) and trace elements (Al, Ba, Be, Cu, Fe, Ni, Sr, and Zn) concentrations confirmed statistically significant interactions in both seasons (summer and autumn). The regression analysis between oxidative stress markers (ROS, GPx, creatinine, uric acid, and bilirubin) and elements (Al, Ba, Co, Cu, Fe, Ni, and Sr) content confirmed statistically significant interactions. The results point to numerous connections between the observed elements and the physiological parameters of freshwater fish.

Species, tissue and gender-related metal and element accumulation in fish species in a large reservoir (Turkey) and health risks and nutritional benefits for consumers

Concentrations of 18 metals and elements (MEs) in the gills, skin, muscle and liver of Carasobarbus luteus and Cyprinus carpio from the Atatürk Reservoir in Turkey were investigated. The results revealed that variations in the ME contents between fish species can be attributed to different diets. The highest contents of most MEs were recorded in the gills. Gender had no significant effect on the contents of most MEs in the tissues of fish species investigated. The relations between MEs in tissues and fish size were not clear and consistent. Health risk assessment methods indicated that consumption of the studied fish species is safe. It was estimated that daily consumption of 140 g of C. carpio or 170 g of C. luteus would not be expected to cause any health risks. Furthermore, it was found that fish species would provide significant benefits in terms of intake of essential MEs.

Investigation of the Metal Pollution Sources in Lake Mogan, Ankara, Turkey

It is important to investigate the monthly level of trace metals in freshwater systems to assess environmental health. This information can be used to support effective management and control of natural areas in regard to the introduction and bioavailability of chemicals in the aquatic environment. We aimed to determine monthly changes in the levels of aluminum (Al), arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), iron (Fe), lead (Pb), mercury (Hg), zinc (Zn), nickel (Ni), and selenium (Se) in water, sediment, and fish samples from Lake Mogan. Five different stations were established in Lake Mogan. Water and sediment samples as well as muscle, liver, kidney, gill, and brain tissues from fish were obtained from these stations every month for 1 year. All analyses were conducted with ICP-OES. In descending order of intensity, the metals identified in the water samples were Fe, Cu, Cr, Zn, Pb, Ni, As, Se, and Hg; those identified in the sediment samples were Fe, Zn, Cu, Ni, Se, Pb, Cr, As, Al, Cd, and Hg; and those identified in fish tissues were Se, Fe, Zn, Cr, Al, Pb, Cu, Ni, As, Hg, and Cd. The most polluted station was located where waste from restaurants and tea gardens were dumped. The level of waste, and thus the level of pollution, was especially high in August. It is concluded that the metals that accumulate in water, sediment, and fish in Lake Mogan originate from anthropogenic activities.