RESUMEN
Two types of artificial reefs, one for simple (S-AR), another for complex artificial reef (C-AR), were installed on a Korean coast of the East Sea (Sea of Japan) where a barren ground was progressive. Compared with macrobenthic organisms at NHB (natural hard bottom) control, AR (artificial reef) enhanced seaweed composition, reducing echinoderm composition, mostly sea urchins, the causative animal of the barren ground. Composition of the two mutually exclusive communities was AR type-specific, the C-AR exerting betterfunction over S-AR by enhancing higher seaweed composition. However this ecosystem-sound composition at C-AR was maintained only within 10 years. Another negative aspect of the AR was an unexpectedly higher composition of tunicates that canbe a sign of nutrient-rich environment in the Korean waters. Overall, CAR was more agreeable when simply based on its function excluding construction cost.