Assessment of Gear Efficiency for Harvesting Artisanal Giant Freshwater Prawn (Macrobrachium Rosenbergii de Man) Fisheries from the Sundarbans Mangrove Ecosystem in Bangladesh

Abstract

The Sundarnbans mangrove forest has been an immense source of aquatic resources from time immemorial. Among the resources, harvesting of Giant Freshwater Prawn (Macrobrachium rosenbergii de Man 1879) plays an important role in the economy of the country, therefore, this investigation was carried out to assess the Gear Efficiency for Harvesting Artisanal Giant Freshwater Prawn Fisheries from the Sundarbans Mangrove Ecosystem in Bangladesh. Four types of non-mechanized crafts made of fourteen types of wood were found in harvesting Giant Freshwater Prawn. Crafts were varied from 6.25±0.35 to 8.2±0.71 m in length, 1.1±0.14 to 1.75±0.36 m in breadth and 0.65±1.07 to 1.55±3.16 m in depth with a carrying capacity of 0.40 - 1.00 MT with an economic life of 10±2.11 years. A total of eight types of gears, namely, Hookline, Behundijal, Badhajal, Charpata, Chandijal, Gillnet, Kathijal and KhalPata were found in Giant Freshwater Prawn fishing. Among them the Hookline was the only main primary active Giant Freshwater Prawn fishing gear while the rest of the seven gears were multi-species gears which harvest Giant Freshwater Prawn as a by-catch. Only 13.6% of 1,989 fishers were found to use Hookline; the rest, 86.4% of fishers used the seven other gears. They only harvest 3.24% Giant Freshwater Prawn as a bycatch. The highest daily harvest volume per boat (kg day-1 boat-1) was 1.00±0.96 for the Kathijal followed by 0.99±0.27 for the Badhajal and 0.99±0.42 for the Hookline. The highest annual catch per boat (kg boat-1 yr-1) which was 172.80±0.29 was recorded for the Hookline followed by 172.24±0.54 for the Chandijal and the lowest (152.08±0.21) for the Khalpata. Total annual catch by all the eight gears surveyed was estimated at 1318.60±0.37 kg from 1,428 unit gears, 545 individual boats and 1,989 individual fishers. Based on the above scenario, Hookline showed the best performance among the 8 gears used for Giant Freshwater Prawn harvesting in the Sundarbans by the small-scale artisanal fishery. It is believed that the findings and the recommendations of this study will be helpful to policy makers in improving the current status of Giant Freshwater Prawn fishery and relevant livelihood as well as conserving the SME ecosystem