Algae are photosynthetic simple eukaryotic organisms - microscopic or macroscopic, aquatic, terrestrial or sub-aerial. Aquatic organisms are found in freshwater or seawater. Algae are adapted to live in a variety of habitats, specific to their microclimatic conditions.
Biodiversity is the variability found in living organisms both plants and animals. The diversity of algal species is mainly concentrated in all aquatic and terrestrial ecosystems. The sea is also considered as the house of a number of variable algal flora popularly known as seaweeds.
The total number of algal species recorded globally is unknown. It has been estimated about 72,536 algal species occur in the different parts of the world, of which only 44,000 species have been already described so far. Only 33,248 names have been processed by Algae Base to date (Guiry, 2015). The databases of Algae Base (Guiry and Guiry 2015) give taxonomic, nomenclatural and bio-geographic information of micro and macro algae from marine as well as freshwater and terrestrial environments on a world-wide basis.
In India, so far, updated checklists or data bases of the algal species are lacking. The main function of biodiversity is to report new taxa and describe them in detail with the help of photographs or clear diagrams showing all taxonomic characteristics. Only skilled and experienced taxonomists are to be involved in this process. In Kerala, extensive study on algal biodiversity has not been conducted to date. Only isolated studies of certain groups from a few regions have been conducted and published papers. Algal flora is rich in Kerala due to its peculiar climatic, and bio-geographic features. Aquatic, terrestrial and sub-aerial algal species occur seasonally. A number of rare and endemic algal taxa are found in the exposed areas of the forests and the high- range areas. The climate of these areas are cool, wet with high humidity. Most of the places of Western Ghats are identified as hot-spots for biodiversity and is considered to be a repository of endemic, rare and endangered flora and fauna. Kerala has a coastal line of 560 km, and rocky coasts are very few with rich algal biodiversity.