Factors Affecting the Fisheries Biodiversity of Ratargul Swamp Forest of Sylhet District, Bangladesh

The study was conducted to identify the factors affecting fisheries biodiversity in Ratargul Swamp Forest under Goainghat Upazila in Sylhet district for a period of 12 months from July 2014 to May 2015. The study was done by questionnaire interviews (QI) of fishes, focus group discussions (FGD), key informant interview (KII) and secondary data collection. During the study period, a total of 94 fish species were recorded where 63 species were found. Among them 28 species are threatened, of which 14 are vulnerable, 10 are endangered and 4 are critically endangered. Highest abundance of commonly available 37 species was found in October to January and lowest species abundance was observed in April to June. It is revealed that there has been gradual reduction of fish diversity in the swamp forest areas that is from the earlier 94 species to present 63 species (32.98% declined). Major factors affecting fish biodiversity were grouped into three categories such as manmade factors, environmental factors and policy issues. Now a day's uncontrolled management of tourism is one of the main factors for reducing biodiversity. During the survey 91.25% respondents navigation is the main factor for affecting biodiversity followed by tourism and fishing. Among environmental factor, 84.1% respondents opened water depth reduction followed by reducing rainfall and high temperature. Community based fisheries management, fishing gear maintenance, afforestation, implementation of fishing acts and regulation, controlled tourism and public awareness can play great role in conserving fish biodiversity. It can be concluded that factors identified in the present study need to be addressed to conserve and enhance fish biodiversity in the Ratargul swamp forest of Bangladesh.