Aged pier of Shimonoseki port was removed, modified to recycled blocks, and used as artificial fish reefs. Two recycled blocks were placed on sandy mud bottom of 40m deep in the coast of Shimonoseki. One was built from 1997 to 1998 and the other was built from 2001 to 2002. The dimension of the block was about 10×8×1.6m and the artificial reef was about 40×100×3m.
To confirm the fish gathering effect, interview survey targeting fishermen and scuba diving survey were carried out from 1998 to 2003. Clear effects on fish gathering were admitted by the surveys. The effects seemed to last at least 5 to 6 years. Before the placement of the fish reefs, discussions with users and stakeholders were held. In the discussions, it was reported that the recycled blocks were legally regarded not as wastes but as valuable materials.
