Recifes artificiais X Recifes naturais: similaridade na cobertura bentônica em função de um gradiente de distâncias em larga escala

Abstract

Artificial reefs (ARs) are man-made structures, which aims to emulate some characteristics of the natural reefs, which have been suggested as a tool for conservation and rehabilitation of the degraded environments. This study aimed to test the following hypotheses: (i) benthic communities from artificial reefs with more than 100 years of introduction are similar to natural rocky reefs and (ii) that these similarities are influenced by the distance among them. Samples were collected in areas subjected to different wave regimes (Exposed and Sheltered), in which, benthic percent coverage were sampled through photoquadrats at 1 shipwreck (AR) and 3 Natural Reefs (NRs), 0 km, 1 km and 2 km far from the RA. In all sampling sites depth, hydrodynamics and the index of rugosity were measured. The ARs were characterized by a lower number of components and high dominance, where Turf represented 50% of the coverage. The NRs were dominated by Zoanthos sp., Protopalythoa variabilis, Echinometra locunter, Turf, Ulva lactuca and calcareous algae. In the Exposed area, the AR benthic coverage showed high dissimilarity among all NRs, and to the Sheltered area the AR was similar only to the 2 km site. Through the multivariate analysis, it was found that there is no significant correlation between the measured environmental parameters and benthic coverage. Both hypotheses raised were rejected and patterns seem to be related more to biological interactions and possible to human impacts.