Seaweeds are macroscopic marine algae attached to solid substratum, growing in the shallow waters of sea.
They are important marine resources exploited for their commercial value as the source of phycocolloids such as agar,
agarose, algin and carrageenan, besides their use as food, source of enzymes, dyes, drugs, growth promoters etc. In
India, seaweeds are harvested from the natural beds along the Tamil Nadu and Gujarat coasts since 1966. The
southeast and northwest coast of India and the Andaman-Nicobar and Laccadive archipelagoes harbour a variety of
seaweeds with rich biomass and species diversity. The standing stock of seaweeds in India is estimated to be 2,60,876
tonnes. It is estimated that seaweed resource of India comprise 6% agarophytes, 8% carrageenophytes, 16%
alginophytes and the remaining 70% green and other non commercial seaweeds. Indian coastline has 624 species of
marine algae belonging to 215 genera and 64 families, of these nearly 60 species only are commercially important.
However, in a revised checklist 844 species of marine algae have been reported from India, comprising 216 species of
Chlorophyta, 191 species of Phaeophyta , 434 species of Rhodophyta and 3 species of Xanthophyta indicating a
considerable increase in the species of seaweeds of India
