Molluscan aquaculture on reefs

Many applications for the use of artificial structures for molluscan aquaculture exist in the world, but only in a few cases have seabed artificial reefs been specially planned for this purpose. The best example of artificial habitat construction for molluscs (i.e. Meretrix lamarckii, Ruditapes philippinarum, Haliotis discus hannai) comes for Japan where marine aquaculture grounds have been created by the deployment of offshore breackwaters, either emersed, immersed or mixed, the excavation of new channels, and the replacement or removal of the existing substrates. The only European model based on the Japanese concept is the "intensive multi-purpose artificial reef" deployed in Italy. This model combines seabed artificial reefs with shellfish culture equipment. The aim is to increase the settling opportunities of drifting bivalve larvae and juveniles whose distribution can extend over a very wide area. Along the Adriatic coast, the deployment of large-scale, commercial, multi-purpose artificial reefs has allowed the development of new exploitable populations of mussels (Mytilus galloprovincialis) and oysters(Ostrea edulis and Crassostrea gigas) in sandy bottom areas far from natural rocky habitats. Artificial reef research in Italy is continuing in order to develop new structures suitable for the settlement and on-growing of other edible bivalves (i.e. Pholas dactylus). The aim is to improve and diversify existing mussel monocultures.