Assessment of fish biodiversity and fishing gear efficiency of the Meghna River at Ramgati Upazila under Lakshmipur district in Bangladesh

Abstract

To analyze the abundance of fish species, the efficiency of fishing gear, catch per unit effort (CPUE), catch composition and the causes of the loss in fish diversity data were collected for six months during July 2023 to December 2023 from the Meghna River, Bangladesh. There was a total of 6 fish species and 1 prawn species, belonging to 7 orders and 7 families and among them order Cypriniformes (21%) was identified most dominant order. The mean values of Shannon-Weaver diversity, Simpson's index, Margalef's richness, and Pielou's evenness indices were measured as 1.862±0.016, 0.976±0.001, 0.537±0.018, and 1.059±0.041, respectively. There is no significance difference (p> 0.05) was observed for the mean monthly fish catch in the present study. Numerous factors, including overexploitation, pollution, and natural causes like siltation may be responsible for a decline in biodiversity. Fish variety in Bangladesh's Meghna River can be greatly enhanced and preserved by using authorized fishing gear, enforcing fish laws and regulations effectively.