Is meiofauna a good bioindicator of artificial reef impact?

Artificial reefs (ARs) are the most common man-made constructions adopted to prevent coastal erosion from wave actions and currents. Despite their worldwide application in coastal management and the documented chemical and physical alterations on surrounding seabeds that they may cause, few studies have been carried out on their impact upon meiofauna. The aim of this survey was to evaluate the potential effects of ARs on the seabed using various meiofaunal descriptors such as the structure of the entire assemblage and of rare taxa, the richness, the diversity indices and the Nematode:Copepod (Ne:Co) ratio. We investigated meiofaunal assemblages of some exposed areas on the Adriatic coast that are protected by ARs and subject to different levels of anthropogenic impact. This last issue was fundamental to examining possible interactions between AR presence and riverine discharges. The results of this study showed that the most efficient meiofaunal descriptors were diversity indices and the Ne:Co ratio, and suggested that the existence of ARs along with uncontrolled riverine discharges may increase anthropogenic impacts upon coastlines. This point is crucial for the conservation and monitoring of beaches because coastal management should be focused on preventing not only coastal erosion, but also possible impacts on marine ecosystem and human health.