Artificial reefs and mariculture

Artificial reefs are natural materials and man-made structures deployed on the seabed to mimic some characteristics of the natural reefs and to improve the aquatic environment. They are included in the more general definition of "artificial habitats", referred to each type of structure deliberately placed in the sea to enhance stocks and fisheries. Many types of artificial habitats are largely used around the world for open-sea mariculture, but the use of bottom artificial reefs is still limited. The only exception is represented by East Asia, especially Japan, where the concept of artificial habitat was initiated and artificial reefs have been systematically applied for extensive mariculture since a long time. Looking at the other countries around the world, some experimental work on the employment of artificial reefs for extensive mariculture has been carried out in the United States with a few invertebrates. In Europe, the only model that is based on the Japanese concept of using artificial reefs to create marine aquaculture grounds was developed in Italy during the last twenty years and is defined as "intensive multi-purpose artificial reefs". It combines bottom artificial reefs witth mariculture, mainly shellfish culture, facilities and has led to the development of large-scale extensive mussel cultures along the coast of the central and northern Adriatic sea. Experience carried out so far shows that artificial reefs may play a relevant role in enhancement of wild populations and in establishment of new marine culture grounds. Planning of aquaculture with artificial reefs must obviously pay attention to the environmental characteristics of the area and to the ecology of the target species. Moreover, in order to optimise results, socio-economic and juridical aspects must be took into account and global management plans involving all the users of the coastal area and establishing measures to regulate gears and fishing effort must be developed.