Abundance and Diversity of Plankton in the Coastal Waters of Chandipur, Bay of Bengal

Abstract

An investigation was carried out at eleven different transect points from 0 to 10 km in the coastal waters of Chandipur, Bay of Bengal (between 21°27′10.4″ N and 87°04′9.02″ E to 21°21′46.54″ N and 87°07′29.41″ E) during winter, summer and monsoon on hydrography and plankton diversity. Productivity in Chandipur coastal water was found to be higher during winter compared to summer and monsoon season. Chlorophyll concentration was 0.32 ± 0.35 mg/m³ in winter, 3.17 ± 0.12 mg/m³ in summer and 2.51 ± 0.16 mg/m³ in monsoon, respectively. Similarly, the average phytoplankton cell count for winter, summer and monsoon season was observed to be 26 618 ± 13 529 cell/L, 14 136 ± 8258 cell/L and 6909 ± 3769 cell/L. Nutrient ratio (N : Si : P) ranged between 5 : 0.1 : 1 to 30 : 0.2 : 1. Two-way ANOVA test (p ≤ 0.001) was tested and showed significant variation in the phytoplankton distribution. A total of 70 phytoplankton species belonging to 36 genera were identified, and Chandipur coastal water was found to be dominated by diatom species. Silicate concentration was comparatively low which could be attributed to the presence of diatoms in coastal water. Species diversity was observed to be maximum in winter (47 species) followed by summer (46 species) and monsoon (35 species) season.