Assessment of the Fish Stock Status Using LBSPR with Its Implications on Fisheries Management: A Case Study of Nemipterus virgatus, Priacanthus macracanthus, and Saurida undosquamis in the Northern South China Sea

Abstract

This study utilized the length-based spawning potential ratio (LBSPR), a data-limited model, to assess the stock status of three fin fish species in the northern South China Sea. The analysis used the “LBSPR” package in R software, incorporating catch-length data of the study species and life history ratios. The results revealed a depletion of the stock’s reproductive biomass for S. undosquamis and imminent risks of stock collapse for P. macracanthus, with SPRs of 10% and 19%, respectively. In contrast, N. virgatus exhibited a relatively high SPR of 32%, surpassing the limit reference point (LRP) (20%). This study identified high fishing pressure (F/M) and the prevalence of destructive fishing practices as contributing factors to stock depletion. Effective management strategies, such as implementing stricter mesh size regulations, reducing catch limits, and reducing fishing efforts, are essential for addressing these issues. Adopting sustainable practices with an SPR target of 40% could lead to economic benefits for N. virgatus. Immediate interventions are crucial for P. macracanthus and S. undosquamis to prevent further declines. Continuous monitoring of the SPR, adaptive management, and active stakeholder engagement are vital for ensuring compliance with conservation measures and achieving long-term sustainability in the region.