Bacci T., Rende F.S., Nonnis O., Maggi C., Izzi A., Gabellini M., Massara F., Di Tullio L., 2013. Effects of laying power cables on a Posidonia oceanica (L.) Delile prairie: the study case of Fiume Santo (NW Sardinia, Italy).
Coastal areas are complex systems where both marine ecosystems and human activity interrelate, often raising several conflicts. The economic activities may, sometimes, disturb the functioning and stability of coastal ecosystems, particularly of the seagrass meadows, and menace their future existence. In the Mediterranean Sea the most important seagrass is Posidonia oceanica (L.) Delile, an endemic species, which meadows have been defined priority habitats following the 92/43/CEE Directive. Therefore, all technical solutions for cables or pipelines installation across a P. oceanica prairie should be adapted in order to protect these ecosystems and to prevent their degradation allowing the maintenance of a satisfactory state of conservation. In this work we present the results of an environmental study carried out in NW Sardinia coast (Italy), where three marine power cables were laid from 2007 to 2010. The technical project, named SAPEI, provided the electrical connection between Sardinian coast and Latium coast through the Tyrrhenian Sea. In the coastal areas colonized by P. oceanica prairies cables were lying on the seabed and anchored with appropriate anchoring devices, placed manually by divers, in order to avoid any damage to the meadows and to prevent cable sliding. Environmental investigations were carried out before, during and after cables installation in order to understand and define how cable laying can interact with seabed. From the end of 2007 to 2011 qualitative (three times a year) and quantitative (once a year) surveys have been performed along the cables routes. Results of environmental monitoring has allowed us to know the health state of P. oceanica in the interested area and it has allowed us to assess, over time, the interactions between seagrass prairies and power lines placed and anchored on it.
