Effects of material types and surface roughness of settlement tiles on macroalgal colonisation and early coral recruitment success

This study assessed the effects of modifying surface roughness across three different tile materials (alumina-based ceramic, calcium carbonate (CaCO3), and concrete) on the settlement success and post-settlement survivorship of Acropora kenti coral larvae. The experiment was conducted at the National Sea Simulator of the Australian Institute of Marine Science, Townsville, Australia in October 2022–February 2023. Tiles were first conditioned for six weeks to allow mixed communities of biofilm and macroalgae to develop, followed by a coral larval settlement choice assay and 10 weeks monitoring of post-settlement survival of coral spat. Tiles were photographed periodically to assess macroalgal communities, larval settlement success, and spat survivorship.