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