Surface integrity could limit the potential of concrete as a bio-enhanced material in the marine environment.

Abstract in brief

• The study compares the marine life on concrete and basalt boulders around Madeira Island to understand how surface integrity affects ecological growth, finding that concrete tends to have lower biomass and fewer organisms than basalt, mainly due to faster surface abrasion.
• Differences in benthic communities were more influenced by location than by substrate type, but overall, substrates in the subtidal zone showed significant variation, with concrete supporting less marine life compared to basalt.
• The reduced biological growth on concrete is likely due to physical abrasion causing the detachment of calcareous biocrusts, rather than chemical effects like heavy metals, highlighting surface integrity as a key factor in the ecological impact of artificial coastlines.