The Impact of Possible Mercury Source-Point Contamination in the Coastal Area of Skiathos Island

Abstract

In Skiathos Island the water is not potable due to mercury contamination and salinization. The mercury’s origin is natural due to the existence of cinnabar in the Skiathos aquifer as a mineral in the Earth’s crust. The possibility of mercury contaminants ending up in the coastal area was investigated through a field experiment. Mussels (Mytilus galloprovincialis) were employed as mercury monitoring biomarkers at the outflow of the wastewater treatment of the island. Using the RNA:DNA ratio, it was revealed that the organisms were stressed after three months of exposure to Skiathos’ coastal waters. The mercury concentration was directly measured at the bulk mussels’ tissue showing differences between the station located at the outflow of the WWT and the reference station. Although the results may imply mercury contamination in the coastal area of the island, the precise origin of the mercury in mussels is difficult to define.