Exploration of fishing activities, fish species assemblage and diversity status of the largest wetland (Arial Beel) near the capital city in Bangladesh: Implications and conservation

Abstract

The wetland named Arial beel is a true reflection of Bangladesh, where the water body is enriched with fish diversity. The purpose of this study was to describe the different types of fishing gear that are available with their characteristics, fish species assemblage and to assess the fish diversity status through sampling in five sampling stations during the study period. A total of 16 different types of fishing gears were discovered in the study, which were divided into eight major categories. There were 61 fish species found in total under 9 orders, 26 families and 45 genera. Cypriniformes (48.02%) was found to be the most dominant order, followed by Perciformes (17.07%), Siluriformes (15.96%), Synbranchiformes (9.33%), Clupeiformes (6.28%), and others (3.35%). Indices of Population viz. Shannon-Wiener's Index (H), Simpson's Dominance Index (D), Simpson's Diversity Index (1-D), Margalef's Index (d) and Gibson's Evenness (€) were used to display species diversity, fish species richness and evenness in sampling areas and the overall values of the indices were 3.36–3.64, 0.033–0.048, 0.952–0.966, 4.74–6.02 and 0.64–0.73 respectively. There was a strong negative correlation between Shannon-Wiener diversity index and Dominance diversity index (r = −0.80936) and a moderate negative correlation between Shannon-Wiener diversity index and Evenness diversity index (r = −0.39911). According to Similarity percentage (SIMPER) analysis 67.29% similarity were found among the stations and 64.71% similarity were observed among the months of fish species. Among 61 fish species of different sampling stations found 5 species are critically endangered (CR), 11 species are endangered (EN) and 12 species are vulnerable according to IUCN red list (2015).