Pesticide and hydrocarbon toxicity in fish: effects on <i>Chelon labrosus</i> (Risso, 1827) along the northeastern Sicilian coast (Italy) evaluated by enzymatic biomarkers

Pesticides intoxication affects aquatic organisms as well as a group of contaminants that are represented by crude oil, petroleum hydrocarbons (PHs), polycyclic aromatic hydrocarbons (PAHs) and their derivatives. Useful tools for ecotoxicological studies of marine ecosystems are based on biomarker application on bioindicator key fish species. The aim of the present study was to highlight the presence of pesticides and hydrocarbons in a coastal marine environment, the harbour of Capo d'Orlando town (northeastern Sicily, Italy), by using the ecotoxicological biomarker Acetylcholinesterase (AChE) and Butyrylcholinesterase (BChE) enzymatic activities in the key fish species <i>Chelon labrosus</i>. A reference site was selected. Chemical analysis of water samples was also carried out to analyze and eventually confirm the presence of pesticides in the study area. Results showed significant inhibition in AChE (80%) and BChE (77%) activities in fish from the harbour of Capo d'Orlando compared to the reference site. The esterase inhibition is primarily due to the presence of organophosphorus insecticides and carbamates, that resulted in higher concentrations of contaminants in the water of the harbour of Capo d'Orlando compared to the reference quality standard decree (Ministerial Decree 260, 2010). This study highlighted the contamination by insecticides and most probably by hydrocarbons in fish from the harbour of Capo d'Orlando, which also represents a threat to the human population consuming affected fish.