水质参数的季节变化及其对Hasadanga Beel鱼类生物多样性指数的影响：案例研究

旨在研究鱼类分集指数及其与Hasadanga Beel的物理化学参数的季节性波动的相关性。对水质参数和鱼类生物多样性指数的季节性波动之间的关系进行了三年的研究，是孟加拉州纳迪亚区的洪泛区，衡量湖泊的生态健康。Samples of water and fish species were collected at pre-monsoon, monsoon and post-monsoon period from 2015-2017 to estimate physicochemical parameters of water and fish biodiversity indices i.e. Shannon-Weaver species diversity index, Margalef’s Species richness index, Pielou’s Species evenness index and Simpson’s index of dominance. Total of 34 different fish species belonging to 8 Orders were found during the study period which varies seasonally. Water temperature (20.0-31.4 °C), pH (7.70-8.75), dissolved oxygen (3.9-5.0 mg/l), Free CO2 (0.0-15.0 mg/l), total alkalinity (156-193 mg/l), hardness (113-145 mg/l), and BOD (1.03-1.94 mg/l) values varied significantly (p<0.05) between three seasons. Shannon-Weaver species diversity index (HêžŒ) is ranged between 1.2911-1.3502, Margalef’s species richness index (D) is measured between 12.72-14.15, Pielou’s species evenness index (JêžŒ) is recorded between 0.8829-0.9140 and Simpson’s index of dominance (ID) is ranged between 0.05346-0.07139. HêžŒ has positive correlation with pH, alkalinity and hardness whereas negative correlation with temperature, free CO2, DO and BOD. D has positive correlation with pH, free CO2, DO and hardness whereas negative correlation with temperature, alkalinity and BOD. JêžŒ has positive correlation with temperature, pH, alkalinity and hardness and whereas negative correlation with free CO2, DO and BOD. ID has positive correlation with temperature, free CO2, DO and BOD whereas negative correlation with pH, alkalinity and hardness. The obtained result suggests that various water quality parameters specially temperature, dissolved oxygen and pH are the key factors to regulate the fish biodiversity indices and should be taken into consideration for making policies for sustainable use of floodplain lakes.