RESUMEN
The estuaries of Maharashtra are under continuous pressure due to uncontrolled dumping of persistent toxic organic pollutants into these regions and their impact on the marine environment. In this study, total petroleum hydrocarbons (TPHs) in water, sediments, fish, and biomarker responses in the Coilia dussumieri exposed to TPHs were determined in seven urbanized tropical estuaries along the west coast of India during the winter and summer. The results of the cluster analysis highlighted that the concentration of TPHs in the water, sediment, and fish in the study area was spatially varied, with the highest concentration in the northern area of Maharashtra (NM) estuaries than in the southern region of Maharashtra (SM) estuaries during both seasons. The enrichment of TPHs in water and sediment in the middle part of most estuaries highlights the addition of anthropogenic organic matter. A higher concentration of TPHs in the muscle tissue of Coilia dussumieri observed in NM during the winter season, indicates the energetic intake and storage of large quantities of TPHs in their muscle tissue. The biochemical results showed decreased levels of total protein (PRT) under exposure to TPHs, under oxidative stress and reversing correlations was observed between catalase (CAT) and lipid peroxidation (LPO) activities with the respective TPHs. Similarly, reduced activity of the CAT antioxidant and increased glutathione-S-transferase (GST) under exposure to TPHs were more likely to occur under hydrocarbon stress. However, current results indicate that Coilia dussumieri actively produces oxidative stress and antioxidant reaction that can be used as biomarkers of pollution in the study area.