Integrated use of biomarkers to assess the impact of heavy metal pollution on Solea aegyptiaca fish in Lake Qarun

Abstract

Background Biomarkers have become a valuable tool in environmental assessment, since they contribute to predicting contaminants in monitoring programmes. This study aimed to investigate the toxicity of heavy metal pollution in Lake Qarun using a multibiomarker approach (morphological, oxidative stress, genotoxicity, stress proteins) in Solea aegyptiaca fish. During the winter and summer seasons, water and fish samples were collected from different locations along Lake Qarun; western and northern sectors were away from any source of pollution, while southern and eastern sectors were exposed to effluents discharged from El-Wadi and El-Bats drains, respectively. The environmental quality, as well as the accumulation of metals (Fe, Cu, Zn, Cd, Pb, Ni) in fish gills, liver, and muscles were assessed. Data were integrated using the integrated biomarker response index (IBRv2) for biomarker response interpretation. Results Water quality and bioaccumulation of heavy metals revealed a highly significant difference between samples collected from polluted sectors and those collected far from drainage water, and, seasonal differences were detected. Growth indices revealed a significant difference between sites and seasons. Fish from the western sector had the highest total antioxidant capacity in their gills, liver, and muscles, with no seasonal differences detected. However, the maximum value of malondialdehyde, protein carbonyl, 8-hydroxy-2′deoxyguanosine, metallothionein, heat shock protein 70, and DNA strand breaks in gills, liver, and muscles was detected in the polluting sectors. It revealed a significant difference between seasons, with the highest value during the winter season. According to IBRv2 results, the most effective biomarkers in this study were malondialdehyde and 8-hydroxy-2′deoxyguanosine in gills, protein carbonyl and metallothionein in the liver, heat shock protein 70 in gills and liver, and DNA strand break in gills, liver, and muscles. Conclusions This multibiomarker approach contributes to distinguishing between locations with varying levels of anthropogenic pollution, identifying the drainage water-exposed sectors as the most stressed and the winter season as the most critical time for Solea aegyptiaca owing to spawning. The biomarkers chosen are effective indicators in Solea aegyptiaca under stress, indicating the potential for environmental monitoring. Graphical Abstract

Biophysical, histological, and bioaccumulation properties of Tilapia muscle affected by water pollution with heavy elements and microbes at the El-Rahawy drain in Egypt

“…On the other hand, the normal architecture of muscle bundle seems to be distorted with breakdown of muscle bundles as noticed in increase in inter muscle bundles spaces. Such notes agree with earlier studies which demonstrated that muscles are very sensitive to contaminants [ 29 , 30 ].…”

Correlations between oxidative DNA damage and formation of hepatic tumours in two flatfish species from contaminated environments

“…Therefore, we assessed the oxidative DNA damage (8-OHdG) from the liver tissue of fish exposed to contaminated environments. The levels of 8-OHdG in aquatic species have been studied as a biomarker of oxidative stress caused by contamination, showing increased levels in populations exposed to higher contamination burdens [49,50]. In our study, increased PAH metabolite concentrations in dabs, but not flounders, were related to higher oxidative DNA damage levels, suggesting that PAH metabolism is linked to increased DNA damage in dabs.…”

Baseline toxicological assessment of biliary PAHs and heavy metals contamination in a commercially consumed native fish (Mugil cephalus) within Fiji coastal waters

“…The HSI in the Laucala Bay mullet was relatively lower than in the Ba River Delta. An increase in HSI may indicate an increase in liver size and/or lipid content and is associated with liver function deterioration, as demonstrated in similar studies 27,34,35 . The HSI values re ected in samples from the Ba River Delta generally indicate poor environmental quality.…”