Plankton Biodiversity and Spatial Variation in the Moheshkhali Channel, Bay of Bengal, Bangladesh

Abstract

This study provides a comprehensive exploration of the pivotal ecological roles played by phytoplankton and zooplankton, highlighting their significance as primary producers and consumers, respectively. Delving deep into the intricate web of environmental factors influencing plankton population dynamics, a meticulous qualitative and quantitative examination was conducted at six distinct stations in the Moheshkhali channel, situated in Cox's Bazar, Bangladesh. The species composition of plankton, as well as the observed species richness and diversity index, exhibited remarkable congruence with the findings of other studies conducted within the same geographical area. In the studied stations, water temperature, salinity, pH, and dissolved oxygen (DO) ranged from 20.94 to 23.90 ºC, 10.60 to 23.98 ppt, 7.60 to 7.92, and 7.7 to 11.7 mg/L, respectively. The density of phytoplankton ranged from 5 to 90 ind × 10³/m³, while the zooplankton population density ranged from 5 to 25 ind × 10²/m³. Among phytoplankton, Rhizosolenia was found to be dominant, but the zooplankton population was dominated by the copepod nauplii stages. Variable ranges of salinity, predation, and environmental factors might be responsible for governing the biodiversity of plankton in this less saline zone of the Bay of Bengal, the Moheshkhali Channel.

The Dhaka University Journal of Earth and Environmental Sciences, Vol. 13(1), 2024, P 155-167