PROBLEM TO BE SOLVED: To provide a technique capable of transplanting seaweed to the seabed in a more natural form. SOLUTION: A transplant assisting material 100 that assists in transplanting a large algae 50 is composed of a three-dimensional net-like fiber material aggregate 10 in which a plurality of fiber materials 1 are locally bonded to each other, and the three-dimensional net-like fiber material aggregate 10 is formed. Has a gap space 15 to which the large algae 50 can directly adhere to the seabed. [Selection diagram] Figure 2【課題】海底に対してより自然な形態で海藻を移植できる技術を提供する。【解決手段】大型藻類５０の移植を助力する移植補助材１００は、複数の繊材１が互いに局所的に接合した立体網状繊材集合体１０を有して成り、立体網状繊材集合体１０は大型藻類５０が海底に直接的に固着可能な間隙空間１５を有している。【選択図】図２
