Diplodus spp. on artificial reefs of different ages: influence of the associated macrobenthic community

Although artificial reefs (ARs) have been deployed and studied worldwide, few studies have attempted to link the benthic community to fish populations. Three AR fish species (Diplodus bellottii, D. sargus, and D. vulgaris) were tested for the influence of the macrobenthic community at three similar ARs deployed in 1990, 1998, and 2002 off the Algarve (southern Portugal). Diplodus sargus density and biomass differed across ARs, and for D. bellottii and D. vulgaris, higher densities and biomass were observed between the oldest and the youngest ARs. The total available benthic biomass did not differ across habitat age, but the composition of macrofauna differed between older and the most recently deployed AR. The results underscore the importance of within-reef-age benthic composition variability as a determinant factor in structuring local fish populations. As the Algarve AR complex consists of reefs deployed at different times and having different benthic communities, management needs to focus more effort on conserving entire habitats rather than exclusively on maintaining the sustainability of fish resources. Hence, management plans for these areas need to be developed on a site-specific basis, according to the fish and macrobenthic community specificities.