Fish biodiversity in Borobila beel of Bangladesh

Background/Question/Methods Biodiversity of fish in beels (natural depressions) have been impacted because of high population pressure, over exploitation and indiscriminate use of fine meshed gears. Additionally, the effects of extensive flood control and irrigation activities have reduced the fish biodiversity and yield in many beels through siltation, habitat destruction, macrophyte infestation and isolation from the seasonal floods restricting entry of riverine fish stocks including impact of stocking enhancement. Considering the importance of biodiversity for sustainable management of natural resources, the present study was conducted to assess the fish and prawn biodiversity in Borobila Beel for 20 months. Borobila beel is located in Rangpur district in northern Bangladesh. It is a semi-closed beel connected with other beels. The approximate water area during rainy season is 700 ha and that during dry season is 50 ha. Water depth varies from 1.8 meter to 3.4 meter.

Results/Conclusions

A total of 58 fish and prawn species were recorded in Borobila beel. Macrobrachium spp. and Puntius sophore were found to be dominant in numerical and weight abundance, respectively recorded in the beel. Beel resident fish was found to be most dominant than those of migratory and riverine fish in terms of abundance (% in number and % weight) in all the beel.  Highest 23 types of gears were observed in the beel. Maximum number of fish and prawn species were recorded in catch of full-time fishers using nets found in all the sampling station of the beels. Catch of Borobila beel represented thela jal (37.05%) and current jal (35.73%) in number (%) and in weight (%), respectively. Results of the present studies indicated that small fish and prawn species form major portion of capture fisheries in Borobila beel. The findings of this study are expected to provide baseline information on biodiversity for sustainable management of beel resources.