Seaweed diversity within intertidal zone of Olaikuda and Vadakkadu, Rameshwaram, southeast coast of India

Seasonal variation of seaweed diversity was studied in Olaikuda and Vadakkadu, the two unexplored coastal areas in Rameshwaram Island in south coast of India. An extensive survey on seasonal changes of seaweed diversity was made study and the data were analyzed for different diversity indices. In each location, 3 transects at 100 m gap were taken and in each transect 10 quadrates, a total of 30 quadrates were taken for seaweeds diversity. The diversity data were analyzed with statistical methods such as graphical and statistical analysis K-dominance curve with software PRIMER package, cluster analysis, multivariate methods, anosim and diversity indices such as Shannon Weaver diversity index, Simpson species richness index, Fisher alpha index, Pielou's evenness, and taxonomic species diversity (delta) index were analyzed by using the software R statistic version 3.1.4. Package (vegan). Totally 74 species including 28 species of Chlorophyceae, 18 species of Phaeophyceae and 28 species of Rhodophyceae were recorded. The study areas are flourishing with 49–59 seaweed species. It is inferred that the seaweeds are well diversified seasonally except summer. The baseline data generated in this work will help in conservation of the seaweeds in the areas.