PROBLEM TO BE SOLVED: To provide a seaweed dissemination body which can be scattered from above the water to a planned development area which solves the problems that although simply scattering (disseminating) seaweed seeds such as seawrack from a ship or the shore onto a planned development area for establishing seaweed beds such as a seawrack bed is the cheapest and easiest means, the light seaweed seeds or seedlings after budding are prone to drifting away due to tides etc. and the preservation thereof in the planned development area until roots of the seaweed have grown has been difficult.SOLUTION: A seaweed dissemination body for dissemination of seaweed from above water comprises a mixed soil of steel slag and seafloor sediment wherein the steel slag content is 50-95 mass% with respect to the mixed soil and the hardness of the mixed soil is at least 500 kPa.SELECTED DRAWING: None
