Stock Assessment of Trichiurus lepturus (Linneaus, 1758) in Zhejiang, China: A Proposal for Fishery Management

ABSTRACT Zhejiang province marine waters are a significant place of commercial fisheries in China as these resources are rich in fish fauna. However, decreased fish biomass catch has been observed during recent years, putting a big question about the ongoing stock status of commercial fisheries. Therefore, this paper strives to appraise the population dynamics of Trichiurus lepturus in Zhejiang, China which would help fishery managers. For this, authentic data, 1999 - 2018, collected from Fishery Yearbooks of China was statistically evaluated through depletion models (DMs). In principle, three models, viz., Fox (FM), Schaefer (SM), and Pella-Tomlinson (PTM) of surplus production models (SPMs), a specialized form of DMs, were used and compared for getting the better-fitted model to draw results. SPMs were applied with the help of computer-based fishery analysis software, i.e., catch and effort data analysis (CEDA) and a stock production model incorporating covariates (ASPIC). In the principle initial portion (IP = 0.9), CEDA output showed higher values of maximum sustainable yield (MSY) (480000 - 614000 t) as compared to ASPIC (468000 - 583000 t). Similarly, R2 values followed the pattern of estimation with MSY. Research findings signpost overexploitation of T. lepturus. Therefore, it is recommended to lower the catch quantity of T. lepturus to safeguard this fishery resource for the future. Besides, further analogous research is strongly advised prior to making or executing any administration strategy.