STUDY OF HYDROBIOLOGICAL PARAMETERS AND THEIR EFFECT ON PLANKTON DIVERSITY IN YAMUNA RIVER AT OKHLA BARRAGE.

The current investigation was conducted on hydrobiological parameters and plankton diversity in the Yamuna River at Okhla Barrage. The various water quality parameters were investigated, and found that the pH ranged from 7.35±0.02 to 8.10±0.09, temperature varied from 20.79±0.02 to 32.29±0.05!, dissolved oxygen (DO) levels range from 1.72±0.08 to 3.6±0.12 mg/l, total dissolved solids (TDS) ranged from 179.625±36.605 to 382.75±0.875 mg/L, electrical conductivity (EC) went from 759.25±9.37 to 1527.25±3.47 μs/cm and free CO₂ levels varied from 8.4±0.93 to 10.5±0.27 mg/L. There are 51 genera of plankton, including 31 genera of phytoplankton and 20 genera of zooplankton. Phytoplanktons are categorized into four major groups: Bacillariophyceae, Chlorophyceae, Cyanophyceae, and Euglenophyceae, and zooplankton belonging to Protozoa, Rotifera, Copepoda and Cladocera. The phytoplankton population exhibited fluctuations, reaching its peak in October (13,000 per litre) and its lowest point in July (10,400 per litre). On the other hand, the highest zooplankton population was recorded in October, reaching 11,600 per litre, while the lowest count was observed in August, with only 5,200 zooplankton per litre. Regarding diversity indices, the highest and lowest values for phytoplankton occurred in July (1.054) and August (0.849), respectively. The diversity index of zooplankton ranged from 1.381 in November to 1.249 in August, with November having the highest diversity index value. [ABSTRACT FROM AUTHOR]