Artificial reefs in Korea

In Korea, artificial reefs have been installed since the 1970s at many coastal areas for the enhancement of fisheries productivity. They are constructed and installed as government-subsidized projects. Reefs installed in Korea include eight designs-five are for fish and the other three are for shellfish or seaweeds. Concrete and steel are used as reef materials, but concrete reefs amount to over 90% of the total installations. Classified on the basis of void space, reef structures are either frame or face (substrate structure) types. Frame structural reefs are used for fish, and face structural reefs are chiefly used for shellfish or seaweeds. Artificial reef size in Korea is divided into the three categories: unit block, reef set, and reef group. Investigation of the effectiveness of artificial reefs in Korea has been carried out since 1975, and six sites are monitored every year. Among the results, the catch volume per reef was 2-13 times greater in artificial reefs than in natural reefs. Korea plans to invest over $2 billion (U.S.) in these projects for the enhancement of coastal fisheries productivity over the next six years.