Limnology of Three Ponds in Chittagong University Campus, Bangladesh

Abstract

Physicochemical characteristics of any water body should be well known before using its water for different domestic purposes and also for different management needs. In Bangladesh, pond water is generally used by the middle to low income classes’ peoples for various purposes ignoring its quality. This study was conducted on monthly basis for two years, from January 2017 to December 2018 to find out the limnological qualities of water of three different types of ponds used by local inhabitants at Chittagong University Campus. The results of twelve limnological parameters were: air temperature (20.1-33°C), water temperature (18-33°C), transparency (14-85 cm), conductivity (22-423 μS/cm), total dissolved solids (TDS: 0-230 mg/l), pH (6.1-8.4), dissolved oxygen (DO: 0.9-16.5 mg/l), biochemical oxygen demand (BOD: 0.8-12.3 mg/l), free carbon dioxide (freeCO2: 2-26.97 mg/l), calcium (Ca++: 1.72-32.68 mg/l), total hardness (4-110 mg/l) and alkalinity (40-98 mg/l). Over use and dumping of household wastes disrupted the normal limnological features of Pond 1, in comparison with other two less (Pond 2) and almost unused (Pond 3) ponds. Extensive use by inhabitants and also physical structure of ponds were found to be responsible for variation and differences among some physicochemical properties of water. Among the three ponds, Pond 1 was found to be extensively used for household uses, than Pond 2 and Pond 3, and thus detected as high, less and not contaminated respectively. Significant direct or inverse correlations were observed among most of the factors.