Linnaeus (1754) was first time gave the name of algae to a group of plants. Agardh (1864) arranged algae in six well-defined orders: Diatomaceae (including desmids), Nostochineae, Confewoideae, Uluaceae, Florideae and Fucoideae and described 20 genera. Significant works during these years were the work of Kuetzing (1843-1849) who described many species. Hassall (1842-1845) made an outstanding contribution in which he recorded many species.

"Diversity is the hallmark of living things on earth today. In its absence the earth's surface would be as monotonous as that of the moon or the planets about which we know". The word diversity means variety, diverseness, differences, variations among the individuals. The term Biodiversity refers to the totality of Genus, Species and Ecosystem of the region. It is fact that all the species can be occurring at one place whether or not a species can occur on a site. It is determined by the environmental conditions of the site and the range of tolerance of the species.