Tahmida Begum

The Relationship of Physicochemical and Biological Variables: with the Seasonality of Microbial Abundance in a Mesotrophic Pond Tahmida Begum

Five pond stations, seven different physicochemical variables, qualitative and quantitative analysis of phytoplankton and bacterial abundance were studied. Relationship among bacteria, phytoplankton and physicochemical variables was investigated. Results showed that air temperature ranged from 14 to 33.5°C, water temperature 19 to 31.5°C, pH 6.59 to 8.95, dissolved oxygen 2.2 mg/l to 9.55 mg/l, conductivity 129.3 to 275 µS/cm, total dissolved solids 73.3 to 121 mg/l, alkalinity of water 1.33 to 2 meq/l, total phytoplankton count 6.7×104 to 744.5×104/l and bacterial count 5.93×101 to 1.50×105 cfu/l. A total of 28 bacterial strains were provisionally identified, out of which 26 from Bacillus and rest 2 strains were from Listeria genus. A total of 139 phytoplankton were recorded from Cyanophyceae, Chlorophyceae, Euglenophyceae, Bacillariophyceae, Cryptophyceae, Dinophyceae and Chrysophyceae where Members of Dinophyceae and Chlorophyceae were dominant and Chrysophyceae was relatively low. Phytoplankton showed a significant positive correlation with pH in station 2 and 4, and negative correlation with air temperature and water temperature in all of the 5 station.