PURPOSE: To contrive to form a fibrous material for organisms for culture of edible marine algae, growth promotion of agricultural and horticultural plants and transportation or freshness preservation of live land and aquatic animals, by blending a fiber-forming high polymer with fine powder of a slightly radioactive mineral and forming the blend into a fibrous state.

CONSTITUTION: The fibrous material for organisms is obtained by blending a fiber-forming high polymer with fine powder of a slightly radioactive mineral and forming the blend into a fibrous state. Fergusonite and allanite are especially preferable as the slightly radioactive mineral with respect to intensity of radiation, easiness of acquisition and cost. 100pts.wt. fiber-forming high polymer is blended with 0.1W60pts.wt. fine powder of slightly radioactive mineral. The particle size of the slightly radioactive mineral is fine as much as possible and the slightly radioactive mineral having ≤32 meshes is usually used.