抄録
Recent climate change has had a significant impact on marine ecosystems. Seaweed production has become less stable and is declining in many traditional seaweed producing areas along the coast of Japan. Against this background, land-based production of seaweed, which can be systematically and stably produced, is increasingly an attractive alternative production method. The Kochi University Marine Botany Laboratory has established a floating seaweed land-based production method which consists of a ″germling cluster method″ proposed for dense tank culture of seaweed in free-floating form and a multistep tank system. In Muroto City, Kochi Prefecture, for the first time the land-based production of an expensive green laver, Ulva prolifera, was commercialized using nutrient rich seawater pumped from over a 300 m depth. After that, several production facilities were put into operation, in which the cost of the capital investment was kept low by using saline groundwater and changing the material from expensive FRP to lowpriced polycarbonate. Most of the production of U. prolifera in Kochi Prefecture has been subsequently replaced by onshore production. The Kochi method has spread nationwide, and as of 2021, an annual total of 20-30 tons of the green laver has been produced. Research is underway to improve the production system and improve efficiency with the aim of applying it to other types of Ulva such as purple laver and using it for purposes other than human nutrition, such as feed for cultured mollusks and for industrial uses.
