Zooplankton in the lower Meghna River and its Estuary with Relation to Physico-Chemical Parameters, Bangladesh
Abu Sayeed Muhammad Sharif, Md. Mohidul Islam, Md. Simul Bhuyan
The present study was conducted to explore the occurrence and distribution of zooplankton of the lower Meghna River Estuary and the effects of ecological variables on the distribution of zooplankton. Samples were collected seasonally at Sandwip, Hatiya Bhola, Barisal, and Chandpur to examine spatial and temporal variability in zooplankton abundance. A total of 37 major zooplankton taxonomic group were identified of which 32 and 23 were recorded during monsoon and post-monsoon season. Water was slightly acidic with very low salinity in major part of the estuary (accept Sandwip 15ppt and Hatiya 10ppt in post-monsoon). The water temperature, secchi depth, H-CO3, CO2, DO, alkalinity, salinity and pH were significantly liable for the variations in zooplankton community structure (p<0.05). Canonical Corresponding Analysis (CCA) revealed that most of the zooplankton showed close affinity to secchi depth, CO2, DO, H-CO3, water temperature and salinity in both season. Temporally the zooplankton diversity (H') did not show much variation (1.10±0.77 and 1.01±0.73 for monsoon and post-monsoon seasons respectively). Bray-Curtis similarity-based hierarchical clustering of zooplankton for sites showed Hatiya and Sandwip from a cluster whereas Bhola, Barisal and Chandpur formed single cluster in the both season.