Abhisek Saha*, Debashis Das and Gobinda Chandra De
The present investigation was carried out on the Torsa, Mansai (Jaldhaka), Raidak-1 river flowing through the Coochbehar district at three spots to access the seasonal variation of physico-chemical parameters with abundance of Barilius bendelisis species. The constituents monitored included viz. Air temperature, Water temperature, Turbidity, pH, TDS, TSS, Total solid, Depth, Conductivity, DO, Free CO2, BOD, Nitrate, Phosphate, Chloride, Total hardness, and total alkalinity. The results of the present study are based upon the observations (n=54) carried out through field sampling between March 2018 to November 2019, and expressed as Catch Par Unit Effort (CPUE). To explain observed changes in CPUE for both sampling years, the data were treated to a two-way factorial ANOVA with sampling locations and seasons as predictor variables. Results suggested that the CPUE varied significantly with the variables at the P<0.05 level. Further, both the years’ data were also subjected to regression analysis concerning physico-chemical parameters. The degree of interrelation among the Physico-chemical parameters is represented through the Pearson correlation matrix. For the first year, the value of correlation coefficient (r) was found highest between pH and Total suspended solid (r=0.97), followed by that of Total suspended solid and Total solid (r=0.77) and pH and Total solid (r=0.73). However, for the subsequent year, ‘r’ was found to be highest between pH and Total suspended solid (r=0.98) followed by Air temperature and Water temperature (r=0.89) and Total suspended solid and Total solid (r=0.77) All these values were positively significant at 0.01 level (2 tailed).