Monsoonal plankton distribution and physico-chemical water qualities in a rain-fed lake in Noakhali, Bangladesh
DOI:
https://doi.org/10.52168/bjf.2020.32.20Keywords:
Rain fed lake, Palmer’s algal pollution index, Wet land zooplankton indexAbstract
The study focused on the monsoonal distribution of plankton in a rain fed partial lake in
Sonapur, Noakhali district, Bangladesh. Three sampling sites were chosen between Sonapur zero point and
Noakhali Science and Technology University. Four groups of phytoplankton such as Chlorophyceae (11
genera), Bacillariophyceae (6 genera), Cyanophyceae (6 genera) and Euglenophyceae (3 genera) and
four groups of zooplankton such as Rotifera (10 genera), Cladocera (3 genera), Copepode (2 genera) and
Crustacea (2 genera) were identified. The lake was found to be organic polluted (Palmer’s algal pollution
index value: 22.33). The average wet land zooplankton index (WZI) value of this lake was estimated 3.72
means moderate water quality. During the sampling periods some important physico-chemical parameters
like temperature (29-30 ?C), pH (7.8-8.2), transparency (6.5-13.50 cm), free CO2 (8.00-12.00 mg/l), total
alkalinity (13.00-14.50 mg/l), ammonia (0.1-0.5 mg/l), nitrate (0.05-0.25 mg/l), nitrite (0.03-0.07),
phosphate (0.1-0.9 mg/l), dissolved oxygen (2-3.5 mg/l) and total suspended solids (4.0×10-4-5.3×10-4
mg/l) were also determined as supporting water quality statement.