PROBLEM TO BE SOLVED: To provide an aquatic organism growth medium supplied with sufficient nutrients such as many kinds of amino acid necessary for the growth of an aquatic organism.SOLUTION: An aquatic organism growth medium is formed by solidification of cement 6, aggregate, and sand 5. At least part of the aggregate is composed of nutrient supply aggregate 3 in which a porous member is impregnated with nutrients for an aquatic organism, and the external surface of the porous member is covered by a coating layer 2 to suppress elution of the nutrients in water.【課題】水中生物の生育に必要な多種のアミノ酸などの栄養素を十分に備えた水中生物生育培体を提供できるようにする。【解決手段】セメント６と骨材と砂５とから固化成形した水中生物生育培体であって、骨材の少なくとも一部が、多孔質材に水生生物に対する栄養素を含浸させると共に、その多孔質材の外表面を水中における栄養素の溶出を抑制する被覆層２で覆ってある栄養供給骨材３からなる。【選択図】図１
