Monitoring on chemical and biological pollutants in sea waters of central-northern Sardinia


Introduction. The aims of this study are to assess the quality of the coastal waters of central-northern Sardinia through data from a monitoring network and to outline maps and experimental models of environmental risk correlated to the presence of chemical and microbiological contaminants. The area studied is the coast between Capo Falcone and the mouth of the river Coghinas, in the northwestern part of the island. Methods. In a first phase, 7 sampling stations of sea water and 1sampling station of bivalve molluscs (Mytilus galloprovincialis Lam.) wereidentified. For each transept 3 different collection points at respectively 500, 1000, and 3000 meters from the coast for a total 21 sampling sites were identified. In a second phase, another 7 transepts wereidentified, 2 of which on the island of Asinara. Results. As regards the microbiological monitoring of the sea water, very low concentrations of Total coliforms, Faecal coliforms and Faecal Streptococci were found and no Salmonella were isolated. Chemical analysis of the waters showed a high constant presence of phenols. In the bivalves we found rather high concentrations of Faecal coliforms without any clear seasonal variation, while no Salmonella was isolated in any of the examined samples. Discussion. The results show that the considered area is not affected by serious pollution processes, thus allowing to express a completely satisfactory judgement on its state of health. However, anthropic pressure in the considered territory is testified by the presence in the water of high concentrations of phenols. Conclusions. The results point out to the necessity of targeted and rational preventive action by means of control and protection measures for environmental ecosytems.