The cost of oyster shell is low, the pretreatment is simple, the raw materials of oyster shell are not easy to mildew, the quality of chitin, chitosan and other products is stable, and the reproducibility is easy to control. Artificial reefs can be made by mixing oyster shell fragments with environmentally friendly concrete. Reef is something that can cultivate bait and is a treasure of nature. It is called marine pasture and fish granary.