PROBLEM TO BE SOLVED: To solve problems in a conventional artificial fish reef using concrete as a main stream in which the material is mineral and is far from the natural environment to be settled as a fish home, and the cut thinning is not caught up as for utilization of the thinned wood of a forest, and therefore the forest is devastated, and further a new demand is asked for the utilization of a steel slug.SOLUTION: When mold concrete blocks are made by utilizing a steel slug, a fish reef is made by embedding wood logs and is laid in the sea after being solidified. The wood logs are made to corrode and disappear with aging after being laid in the sea, and hollow holes are left thereto. The wood logs serve as supply of organic matter to marine creatures when corroding and disappearing in the sea, and by the effect, the surfaces of the blocks make the environment suitable for growth of algae. The holes made after the corrosion and disappearance of the wood logs become suitable places as the fish home. By this technique, the effective utilization of the thinned wood and the steel slug is promoted, and it can contribute to the promotion of the coastal fishery.SELECTED DRAWING: Figure 2【課題】従来の人工漁礁は、コンクリートを用いたものが主流であったが、材質が無機質で、魚の棲み家として定着するには自然な環境とはほど遠いものがあった。 また、山林の間伐材の活用は間伐手入れが追い付かず、山林が荒廃するという課題があった。 更に、鉄鋼スラグの活用面でも新たな需要が求められていた。【解決手段】鉄鋼スラグを活用し、型枠ブロックを製作する際に、木材丸太を埋め込んで漁礁を製作し、固形化したのち海中に敷設する。海中に敷設した後は経年と共に木材丸太は腐蝕消失しそのあとに空洞の穴が残る。 木材丸太は海中において腐蝕消失する際、海中生物への有機質の供給をつかさどり、その効果によりブロックの表面は藻の繁殖に適する環境を作る。木材丸太の腐蝕消失の跡にできた穴は、魚類の棲み家として格好の場所となる。 この技術により間伐材と鉄鋼スラグの有効利用を促進し、また、沿岸漁業の振興に寄与できる。【選択図】図２
