Assessing Bycatch Vulnerability in Hilsa Gillnet Fishing Along the Southeastern Coast of Bangladesh Using Productivity and Susceptibility Analysis ( PSA )

Abstract

Hilsa the cornerstone of Bangladesh's marine fishing industry contributes significantly to the national economy through providing food, nutrition, employment and foreign exchange. In Bangladesh the primary method for capturing Hilsa revolves around the widespread use of gillnets. However, the extensive use of gillnets give rise to concerns about potential negative impact, particularly in terms of bycatch. Therefore, this study employed a data‐poor method, productivity and susceptibility Analysis (PSA) to evaluate the bycatch vulnerability in gillnets of 15 commercially important fish species from the coast of Bangladesh, including Hilsa. These species were selected through an extensive questionnaire survey along the coast of Chattogram and Cox's Bazar district. The result indicates that Lepturacanthus savala had the lowest productivity value, scoring 1.30. Given that Hilsa is the primary target species for gillnet fishing, it exhibited the highest susceptibility score of 2.92. Among the 15 species four species Tenualosa ilisha , Eleutheronema tetradactylum , Lates calcarifer , Polynemus paradiseus also showed elevated susceptibility with score of 2.92, 2.43, 2.47 and 2.83 respectively. Species with low productivity and high susceptibility exhibited comparatively higher vulnerability scores. Among all the species analyzed about 79.37% showed a moderate level of risk, 8.07% indicated low risk and 18.59% were classified as having a high risk of bycatch in gillnet. Lates calcarifer and polynemus paradiseus showed higher risk of being bycatch in gillnets with vulnerability score of 2.03 and 2.00 respectively. Conversely, Coilia dussumieri had the lowest risk with a vulnerability score of 0.85. Though PSA is characterized by several limitations, including the unavailability of species‐specific life‐history and susceptibility data, reliance on proxy values, and inherent subjectivity, this approach offers a transparent and precautionary framework for assessing species vulnerability in data‐poor fisheries and serves as a rapid screening tool to inform management priorities. Therefore, this study emphasizes the necessity of improving data collection on species‐specific life‐history traits to enhance the accuracy and reliability of vulnerability assessments.

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