Settlement on concrete blocks immersed in the Ligurian Sea (N-W Mediterranean)

Within the framework of a study on the behaviour of recycled materials in the sea, cubic concrete blocks (used as control material) were immersed at two different locations (Loano and Lavagna) in the Ligurian Sea. The study started in November 1993 and ended in December 1994. In order to gain an idea of the different settlement periods and of the subsequent evolution of the population present on the substrata, these concrete blocks were taken away for faunal analysis and replaced by new blocks every three months. Each block settlement was described, both in terms of quality (species present) and quantity (covering indices, wet weight, dry weight and ash weight). The total number of taxa found in the two localities was 53, 26 of which were common to both sites. The pattern of community development was quite similar and the one year biomass was slightly higher in Loano with 14.2 g/dm2 of wet weight (8.3 dry weight, 6.7 ash weight) while, in Lavagna, 12.2 g/dm2 wet weight (6.7 dry weight, 6.1 ash weight) was reached.