Length-Based Stock Assessment for the Data-Poor Bombay Duck Fishery from the Northern Bay of Bengal Coast, Bangladesh

• Published in: Journal of marine science and engineering Vol. 10; no. 2; p. 213
• Main Authors: Alam, Mohammed Shahidul, Liu, Qun, Schneider, Petra, Mozumder, Mohammad Mojibul Hoque, Chowdhury, Mohammad Zahedur Rahman, Uddin, Mohammad Muslem, Monwar, Md. Mostafa, Hoque, Md. Enamul, Barua, Suman
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.02.2022
• Subjects: Biomass; Bombay duck; Catch per unit effort; Codends; Commercial fishing; Data collection; Employment; Evaluation; Exploitation; Fish; Fisheries; Fisheries management; Fishery data; Fishing; Fishing effort; Fishing pressure; Harpadon nehereus; Impact analysis; Juveniles; length-based indicators; low SPR; Marine fish; Marine fisheries; Mortality; Nutrition; Overexploitation; Parameter estimation; Production increases; Regulatory agencies; Responsible fisheries; Spawning; Spawning potential ratio; Stock assessment; Sustainability; Sustainability management; Sustainable fisheries; Bangladesh
• DOI: 10.3390/jmse10020213
• ISSN: 2077-1312

The Bombay duck (Harpadon nehereus) forms the second-largest single-species marine fishery in Bangladesh and therefore has a significant impact on the local economy, providing employment, food, and nutrition to thousands of people. Despite the immense importance, this fishery has never been a priority for the relevant regulatory authorities. To enhance the sustainability of this fishery, an effective management policy based on the scientific evaluation of the current stock’s status is urgently required. Therefore, this study used three methodological approaches (traditional size structure-based stock assessment to reveal current exploitation status; the length-based spawning potential ratio (LB-SPR) to evaluate the stock’s spawning biomass; and Froese’s sustainability indicators for sustainable fishing) to conduct a thorough assessment of the Bombay duck stock to establish basic standards for the sustainable management of this fishery. The results revealed that this fishery is presently suffering from overexploitation and the stock’s spawning biomass (SPR = 8%) is below the limit reference point because of the juvenile-oriented fishing behavior of the fishery. Based on the outputs, this study recommended the mesh size regulation of the set bag nets (SBNs) (5 cm mesh size for the codend) to ensure not to catch immature fishes with a length equal to or smaller than 17.95 cm; and reduce the existing number of SBNs by half to reduce fishing pressure on the stock to ensure the sustainability of this fishery.