PROBLEM TO BE SOLVED: To provide a fishing bank, because the fact that the life of timber from forest-thinning installed in the sea is as short as five years at the most is a big obstacle to installation of the timber from forest-thinning as fishing bank in public works, in which the years in function and life as a fishing bank of the fishing bank made of timber from forest-thinning is extended as long as that of a fishing bank made of concrete, in which a cast or special panel is not used in the production process, in which substandard material is also used effectively, and in which the used ratio of timber from forest thinning and hardening material is adjustable.SOLUTION: Hardening material is installed inside the frame structure, which is made by piling up timber from forest-thinning in the shape of curb and further to which timber from forest-thinning is inserted, and the structure is placed in the seabed. After several years, the timber from forest-thinning decays and a tunnel-like space is naturally created inside. The space serves as a suitable living space for aquatic life, and holds the proliferation function for a long period which secures the life of the fishing bank in question. The structure, which is stiff and excellent in stability and whose material is obtained at a low cost, is also easy to produce. Substandard lumber remnants are also effectively used and used ratio of the material varies by altering the number of stages of the curb, the number of insertion, or the like.【課題】 海中に設置した間伐材の耐久年数は最大５年程度と短く、公共事業で間伐材魚礁を設置する際の大きなネックとなっている。この発明の最も重要な課題は、間伐材活用魚礁の魚礁としての機能持続年数及び耐用年数をコンクリート製魚礁と同等まで増大することにあり、かつ型枠や特殊なパネル等を使用せずに製作でき、規格未満の端材も有効活用でき、間伐材と硬化体の使用比率が調整可能な魚礁の考案にある。【解決手段】 間伐材を井桁状に組み上げ、さらに間伐材を挿入した枠構造物の内部に硬化体を打設し、海底に設置する。数年後には間伐材が腐朽・消失し、内部にトンネル状空間が自然形成される。この空間は水産生物にとって好適な生息場となり、増殖機能が長期間保持され、課題の耐用年数が確保できる。頑強で安定性に優れ、材料を安価に調達でき、製作も容易であり、規格末満の端材も有効活用でき、井桁の段数、挿入本数などを変更することで材料の使用比率を増減できる。【選択図】図３
