PROBLEM TO BE SOLVED: To achieve soft and porous artificial corallite similar to corals by utilizing a magnesium-based solidifying agent in a neutral region, and to provide a method for proliferating corals, and a method for improving an environment for marine life such as a fishing bank block.SOLUTION: By adopting the method for improving an environment for marine life whereby marine algae, algae or burrowing animals can grow easily in a porous material part by using artificial corallite obtained by forming a porous material similar to stony corals, growth of marine life such as marine algae, algae or burrowing animals is facilitated, and the undersea environment is improved. Further, since the artificial corallite is produced by being formed and cured under room temperature, the shape or the size can be obtained optionally.【課題】中性域のマグネシウム系固化剤を利用して、サンゴ同様な軟質で多孔質の人工サンゴ石を実現し、サンゴの増殖方法や漁礁ブロックなど、海中生物用の環境改善方法を提供する。【解決手段】イシサンゴ同様の多孔質を形成してなる人工サンゴ石を使用し、多孔質部に海藻や藻や穿孔動物が生育し易くした海中生物用の環境改善方法であるから、海藻や藻や穿孔動物などの海中生物が生育し易くなり、海中の環境が改善される。しかも、常温下で成型し養生することによって製造されるので、形状や大きさは任意である。【選択図】図５
