Commercial importance of marine macro algae

India with a vast coastline of more than 8000 km supports a rich standing crop of marine \nalgae wherever rocky or coral formations occur along the coast. The current estimate of \nannual standing crop of marine algae of India is 3, 01,646 tonnes (fresh weight).The algae \ncontain minerals, trace elements (iodine and bromine), proteins, carbohydrates, lipids etc.The \nmarine algae are a good source of organic constituents such as vitamins, bioactive substances \nand polysaccharides and also are useful as raw material for biofuel production and liquid \nfertilizer. Important polysaccharides obtained from algae are agar, carrageenan and algin. \nThe Indian red algae such as Gelidium, Gelidiella, Pterocladia and Gracilaria yield agar and \nagarose. Agarose is the most important medium for electrophoresis. The red algae viz. \nHypnea, Kappaphycus, Acanthophora, Laurencia are the sources of carrageenan. Algin is \nextracted from brown algae like Sargassum, Turbinaria, Hormophysa and Cystoseira. \nMannitol is also obtainable from brown algae. This is used as a diuretic and helps in \nexcretion of some toxins. Many of the green, brown and red algae form part of the diet taken \nby people of South East Asia. In India, the red alga Gracilaria edulis is eaten in certain \ncoastal areas of Tamil Nadu as porridge. Some of the marine algal constituents are of \nantimicrobial, antifungal, antiviral, diuretic and spasmolytic values. The algae are used in the \ntreatment of goiter and as ichthyotoxic compounds. Other medicinal properties and \ncommercial uses of algae in industry and biotechnology are reviewed in this paper. Efforts \nmust therefore be made by concerned agencies and entrepreneurs to make best use of the \nrenewable marine algae which are available along our coasts.