Impatto dell’attività di maricoltura off-shore sull’ecosistema bentonico: caso studio in corso presso un’azienda ittica sarda (Rada di Alghero)

Intensive cage aquaculture generates considerable quantities of waste, including both particulate uneaten feed, fish faeces and soluble excretory products. These wastes can have undesirable impacts on the local environment, depending on the amounts released, the time-scale over which the releases take place, and the assimilation capacity and flushing ability of the local recipient water body. The aim of this study, therefore, was to assess the effects of mariculture activities located in the Alghero Bay (western Mediterranean) on the benthic ecosystem. The analysis of organic fraction, carbonate, inorganic residue and macrofauna abundance (species/m2, individuals/m2, Shannon-Wiener diversity index, Simpson’s Index and evenness) in sediment samples (inside and outside of the mariculture area) show a local effect on the benthic ecosystem under the cages position. Therefore, two control samples, positioned towards the major current direction, are similar to all samples located under the fish farm, a sing of wider effect of the aquaculture activity.