Polycyclic aromatic hydrocarbons levels and potential biomarkers in a native South American marine fish

Polycyclic aromatic hydrocarbons (PAHs) cause adverse effects on ecosystems and organisms from aquatic environments due to their toxicity, persistence, and bioaccumulation characteristics. Furthermore, PAH exposure in fish can induce hepatic damage and physiological/biochemical disorders. The use of biomarkers can be a useful diagnostic tool to measure the health of an ecosystem, detecting alterations in organisms that can serve as early warning indicators of pollution. The present study assesses the levels of 17 PAHs in sediments and muscle of a wild fish (Cynoscion guatucupa) from the Bahia Blanca Estuary (BBE), Argentina. The concentrations of PAHs found in fish were correlated to lipid peroxidation (thiobarbituric acid reactive substances, TBARs), the activity of metabolic enzymes (alanine aminotransferase [ALT], aspartate transaminase [AST], and lactate dehydrogenase [LDH]) in liver and muscle tissues, and the condition factor (CF) to test their usefulness as integrated biomarkers of PAH pollution in field samples. Results showed most frequency of 2–3 ring PAHs and higher concentrations of 4 ring PAHs; total PAHs ranged from 11.27 to 52.80 ng.g−1 (w.w) for fish and 37.5 to 380.5 ng.g−1 (d.w) for sediments. Total PAHs in fish positively correlated to muscle TBAR levels (p<0.05), suggesting that lipid peroxidation could be produced by the pollutants. Moreover, total PAHs in fish muscle correlated positively with muscle LDH activity (p<0.01) and negatively with liver AST and ALT activities, suggesting a shift to anaerobic metabolism under stress conditions and possible hepatic damage in C. guatucupa, respectively. The minimum CF and the maximum growing coefficient were observed with maximum concentrations of total PAHs in muscle. According to the methods and data presented, we can propose TBARs, LDH, AST/ALT, and CF as integrated early warning tools to assess PAH pollution effects in the native commercial fish Cynoscion guatucupa in South American marine environments.