First of all, I want to introduce about the artificial reef.
artificial coral reef is “a submerged structure placed on the substratum (seabed) deliberately, to mimic some characteristics of a natural reef”How are important artificial coral reef ? = Design-related factors of AR such as number and size of holes, reef-group size and spatial arrangement of AR units, may affect fish abundance, biomass, and species richness Thus, bigger and more heterogeneous AR could accommodate more abundant and richer fish assemblages