Distribution and Seasonal Abundance of Algal Forms in Chilka Lake, East Coast of India.

Abstract

Studies on monthly variation of physico-chemical features and phytoplankton population of Chilka lake during January to December 1989 has been made and compared the differences among four different sectors of the lake. In addition, certain hydrographical parameters of the lake and distribution of algal forms in its different sectors was also studied during March 1988 to June 1990. Seasonal fluctuation of physico-chemical features depends on the discharge of fresh water by catchment rivers and inflow of salt water from sea.Phytoplankton population was rich in the southern sector and poor in the northern sector. The composition of phytoplankton in different sectors in the same month were heterogeneous. The major groups of phytoplanktons were diatoms and blue-green algae. The diatoms were abundant in southern sector, where autochthonous species were dominated showing small two peaks in July and October 1989, and outer channel sector, where allochthonous species were dominated throughout the year. The blue-green algae were abundant in the central sector and northern sector. Of the dominant seaweeds, Chaetomorpha linum was widely distributed in the lake followed by Enteromorpha intestinalis, E. compressa, Ulva lactuca and Cladophora glomerata. The agarophyte, Gracilaria verrucosa, which was occurring widely in the lake five decades ago, is now restricted to a specific area in the central sector.