Habitat and Biodiversity Degradation of the Surma River, Bangladesh and Implications for Future Management

Abstract

The investigation was carried out to provide an overview of the current resources and fisheries status of the Surma River and existing fisheries management strategies, especially focusing on fish diversity and conservation. Surma River is one of the largest aquatic ecosystems of Bangladesh and support huge amount of diverse fisheries communities. A monthly fish catch survey was carried out from March to August 2017 in the three most important catchment areas of Sylhet district; namely, Kushighat, Kanishailghat and Tuker bazar. It was completed by questionnaire interviews of fishers, focus group discussions, key informant interviews, and secondary data collection. A total of 16 different types of fishing gears were identified from the study area. Among these 7 lift net, 1 dip net, 2 gill net, 2 seine net, 1 cast net, 1 push net, and 2 hook and line were identified. The highest gear efficiency (0.77±0.06 kg.gear–1.h–1.person–1) from thela jal (Push net) in August and lowest (0.167±0.03 kg.gear–1.h–1.person–1) from jimti jal (Lift net) in March were recorded. A total of 18 sampling stations identified 53 fish species under 8 orders and 21 families, including prawns. Cyprinidae was the leading family consisting of 34% of the total fish population. The Shannon- Weaver diversity index (H’) was found uppermost (2.68) in August and lowermost (2.14) in May. Margalef richness index (D) was found maximum (4.86) in June and minimum (1.62) in March. Contrariwise, Pielou’s evenness index (e) was highest (0.98) in March and lowest (0.61) in May. However, richness index varied significantly different in all the month except in July and August (P<0.05). In 2016, the annual fish production was 268.13 MT, being almost three times than observed in 2012. Several management strategies were suggested by the stakeholders, and the findings are discussed in the context of overall developments in the Surma River fisheries related to habitat and biodiversity management.