Environmental assessment of the pesticides in Parablennius sanguinolentus along the Western Calabrian coast (Italy)

The accumulation and persistence of chemical pesticides in aquatic ecosystems represent serious threats to both fish and humans. Useful tools for ecotoxicological studies of marine ecosystems are based on biomarker application to key fish species. The main aim of the present study was to investigate the presence of pesticides in a coastal marine environment, as the tourist port of Bagnara Calabra on the western Calabrian coast of Italy. This was based on acetylcholinesterase and butyrylcholinesterase enzymatic activities as biomarkers in the key fish species Parablennius sanguinolentus. The reference site of Jancuia Cove was also investigated. There was significant inhibition of these acetylcholinesterase (23.5%) and butyrylcholinesterase (72.0%) activities for Bagnara Calabra Port compared to Jancuia Cove. The esterase inhibition was primarily due to carbamate and organophosphorus insecticides, which showed higher concentrations for Bagnara Calabra Port (means, 1.0 μg L−1, 0.14 μg L−1, respectively) with respect to the reference quality standard set by Italian Law. These data indicate the presence of insecticides in the waters of Bagnara Calabra Port that might represent considerable hazard to humans, as the surrounding areas include bathing and recreational fishing activities throughout the year. This study also confirms the benefits that can be gained from such a biomarker-based approach when applied to a fish species for the monitoring of water ecosystems, to define the ecotoxicological, and the consequent ecological, alterations.