Investigation of Seasonal Functional Dynamics of Plankton in Relationship with Physicochemical Variables in Point Calimere Wildlife and Bird Sanctuary

Abstract

The study reveals the seasonal variation of physicochemical parameters and their functional dynamics on plankton density, diversity, richness, and evenness in Kodiakarai (also known as Point Calimere) wetland Bird Sanctuary. Quantitative samples were collected every month from September 2021 to June 2022 at Kodiakkarai, Bay of Bengal (BOB) coast. Statistical analyses of physicochemical parameters: temperature, salinity, pH, dissolved oxygen, nitrate, nitrite, phosphate, and silicate were performed. The significant variation across seasons as well as the high influence of physicochemical changes of plankton productivity were observed. A total of 40 species: viz. 28 species of Bacillariophyceae, 7 species of Dinophyceae, 2 species of Cyanophyceae and 3 species of Chlorophyceae were recorded in station I; whereas 34 species: viz. 22 species of Bacillariophyceae, 6 species of Dinophyceae, 4 species of Cyanophyceae and 2 species of Chlorophyceae were recorded in station II. In both stations, calanoid was found (40%) dominated, further 32% of Cyclopoida and 28% of Harpacticoida were recorded in station I; whereas 35% of Cyclopoida and 25% of Harpacticoida were recorded in station II. Therefore, a total of 25 and 20 species were recorded during the study period. The statistical analysis of plankton species, including the Shannon−Wiener diversity index, Simpson’s richness index, and Pielou’s evenness index, revealed higher values during the summer season and lower values during the monsoon season. The study found that the productivity of the Kodiakarai wetland contributes on dietary of about a hundred bird species, annually. Among the bird species, a major portion of large wading bird dominance was noted in the Point Calimere Wildlife Sanctuary during the study period.