Benthic diatom communities and a comparative seasonal-based ecological quality assessment of a transboundary river in Bangladesh

Abstract

Seasonality can play a crucial role in altering water quality in tropical rivers, and as a benthic community, diatom can show seasonal variation and changes in ecological status. During the present study, the Trophic Diatom Index (TDI) and Water Quality Index (WQI) were used to determine the ecological status of a transboundary river, the Sari-Goyain River in Bangladesh. Samplings were carried out from upstream to downstream river sites in wet and dry seasons to observe the seasonal dynamics. The benthic diatom composition and physicochemical parameters showed seasonal variation in ecological water quality assessment. In the River, 42 different diatom species from 19 genera were recorded. The mean TDI values indicated an oligotrophic condition of the river in both seasons. But, the WQI values showed excellent and good water quality in the wet and dry seasons, respectively. So, the WQI was helpful in assessing seasonal variation of ecological water quality status in the Sari-Goyain River. For the long-term monitoring of the ecological status of the river, seasonal variation and WQI-based assessment should be considered.

Advancing River Health Assessments: Integrating Microscopy and Molecular Techniques through Diatom Indices

“…Its advantages include diatoms' high sensitivity to changes in water quality, making them reliable early indicators of shifts in ecosystem health. Diatom records also offer insights into historical water quality trends, illustrating the effects of human activity and environmental changes over time, as demonstrated in numerous studies [29][30][31]. However, challenges such as the necessity for region-specific indices due to regional variation and the requirement for taxonomic expertise to avoid misidentification and inaccurate assessments persist.…”