title: How complementary are epibenthic assemblages in artificial and nearby natural rocky reefs?
abstract: The present study analyses the composition, structure and trophic function of epibenthic assemblages in two artificial reefs (ARs) 16 years after deployment and in nearby natural reefs (NRs), aiming at providing insights on the complementarity between both habitats. Current findings suggest that after 16 years the ARs (concrete blocks), located in southern Portugal, do not act as surrogates for NRs, as epibenthic assemblages differed between reef types in composition, structure and trophic function. NRs showed higher diversity and complementarity (i.e. beta-diversity) than ARs, evidencing higher redundancy. Higher heterogeneity within NRs was also evidenced by the multi-dimensional scaling analysis based on abundance, biomass and trophic composition. NRs presented higher abundance of molluscs and biomass of sponges, resulting in differences in the trophic function: suspension-feeding dominated the NRs, while within ARs there was an ascendency of carnivory. Although not acting as surrogates for NRs and provided that no adverse effects (e.g. establishment of non-native species) were detected, ARs may have a significant contribution for the increase of regional diversity, as evidenced by the highest complementarity levels observed between assemblages in both reefs.
authors.affiliation: IPMA - Portuguese Institute for the Sea and Atmosphere, Av. 5 de Outubro s/n, 8700-305 Olhão, Portugal.
authors.forename: Susana
authors.initials: S
authors.lastname: Carvalho
authors.forename: Ana
authors.initials: A
authors.lastname: Moura
authors.forename: João
authors.initials: J
authors.lastname: Cúrdia
authors.forename: Luís
authors.initials: L
authors.lastname: Cancela da Fonseca
authors.forename: Miguel N
authors.initials: MN
authors.lastname: Santos
mesh_terms: D000818:Animals; D059001:Aquatic Organisms; D001267:Atlantic Ocean; D044822:Biodiversity; D018533:Biomass; D003247:Conservation of Natural Resources / Q000379:methods*; D057894:Coral Reefs; D017753:Ecosystem; D008974:Mollusca / Q000502:physiology; D011156:Population Density; D011161:Porifera / Q000502:physiology; D011174:Portugal
keywords: Artificial habitats; Beta-diversity; Community composition; Community function; NE Atlantic Ocean; Natural rocky reefs