Abstract

Three years of summer sampling, from 1999 to 2001, have permitted the verification of a close relationship between the depletion of Posidonia oceanica bed in Maddalena National Park (NE Sardinia) and several factors of anthropogenic origin. Among them, the increase in water turbidity and the effects of boats anchoring on the sea floor are the principal causes for the reduction ofthe density, leaf length and coverage of the phanerogam. 78 circular areas 40 meters in diameter has been monitored by SCUBA diving, glass floored inflatable dinghy and a high definition (600 kHz) side scan sonar with a coverage of approximately 300 hectares, allowing the identification of the most affected areas and the quantification of the effects. The consequences of these effects on P. oceanica beds are evident by comparison with the values measured in non affected areas.

I documenti depositati in UnissResearch sono protetti dalle leggi che regolano il diritto d'autore