Natural and anthropogenic impact on lysosomal response of Mytilus galloprovincialis Lamarck 1891

This study advances environmental monitoring by combining histopathological and biochemical biomarkers in Mediterranean mussel (Mytilus galloprovincialis), with particular attention to acid DNase activity as a fast and reliable parameter. By addressing both natural physiological variations and pollution-driven stress responses, it strengthens the accuracy of biomarker-based assessments. Natural variations in lysosomal histochemical parameters (lysosomal membrane stability, neutral lipids and lipofuscin content) and acid DNase activity in the digestive gland of mussels from a pristine (St. Andrew) and a polluted site (ACI Marina) from the Northern Adriatic were analyzed monthly. Acid DNase activity showed a low correlation to temperature and salinity, indicating its potential as a reliable parameter for environmental monitoring. The integration of acid DNase activity and lysosomal histochemical biomarkers allowed for a clearer differentiation between the pristine site and the area affected by anthropogenic impact. The findings identify April to July as the most suitable period for detecting pollution impacts, and they demonstrate that integrating lysosomal biomarkers with the rapid acid DNase activity provides clear site differentiation without interference from mussel physiology. The speed and reliability of acid DNase activity make it especially promising for future environmental assessments, offering a practical and efficient tool for routine monitoring in the Adriatic and Mediterranean, where mussels are widely used as sentinel species for coastal ecosystem health.