Preliminary results from the establishment of experimental artificial reefs in the N. Aegean Sea (Chalkidiki, Greece)

Twenty-four artificial reef units were designed and set in the coastal waters off Neos Marmaras (Chalkidiki, North Aegean Sea, Greece) in July 1998, at depths ranging between 7 and 22 in. The volume of each unit was between 0.8 and 2.25 m(3) and the maximum weight was up to one t. Three different types of material were used for the construction of the units, namely cement, ceramic and car tyres. The units were set along a main axis and along secondary axes that were perpendicular to the main one. The artificial reef units were monitored both directly, by diving, as well as through underwater photos and experimental sampling. Our results indicated that there was a tendency: (a) of sessile organisms to inhabit the reef units and (b) for fish to find refuge in the reef units with higher number of species generally recorded after the deployment of the reef units.