基于CMSY和BSM的东海区重要渔业种类资源评估

有限数据方法(data-limited method)可结合少量易获得数据和相关生物学信息对渔业资源状况、生物学参考点以及生物量等进行评估,已经成为全球区域性渔业管理组织和资源评估学者的关注热点。本研究采用基于渔获量的最大可持续渔获量(catch-based maximum sustainable yield,CMSY)和基于贝叶斯状态空间的Schaefer产量模型(Bayesian Schaefer production model,BSM)评估了东海区19个重要经济种类的资源状况,并提出了基于最大可持续渔获量(maximum sustainable yield,MSY)的渔业管理建议。结果显示,19个种类中有1个种类衰竭,3个种类严重衰退,5个种类过度捕捞,5个种类轻度过度捕捞,5个种类健康。种群状态长期评估结果表明,处于生物可持续水平的鱼类种群占比已由1980年的95%下降至2019年的26%。同时对CMSY和BSM方法的结果进行了比较,整合单位捕捞努力量渔获量(catch per unit effort,CPUE)数据的BSM方法导致了置信区间较宽,并调节了生物量轨迹的变化形态...

Assessment of commercially exploited fish stocks in the East China Sea using CMSY and BSM analysis

Stock assessment involves providing scientific and quantitative evaluations to objectively inform fisheries management. However, data limitations are a common challenge for global stock assessments. Many exploited fish stocks in China lack quantitative assessments due to the limitations imposed by the data requirements of conventional stock assessment methods; ultimately, this hinders the advancement of total allowable catch (TAC) systems in China. The catch-based maximum sustainable yield (CMSY) and Bayesian Schaefer production model (BSM) are recently developed methods that are most suited for calculating the intrinsic population growth rate (r), carrying capacity or unexploited stock size (k), maximum sustainable yield (MSY), and other reference points of data for fishery management. Reference points for 19 commercial groups exploited by Chinese fisheries were calculated over time using CMSY and BSM methods by evaluating catch and abundance levels. The results showed that one stock collapsed, three stocks were severely declined, five stocks were overfished, five stocks were slightly overfished, and five stocks were healthy. The long-term assessment of stock status demonstrated that the proportion of stocks at biologically sustainable levels declined from 95% in 1980 to 26% in 2019. We also compared the CMSY and BSM methods. The BSM method, which integrated CPUE data, resulted in wider confidence intervals and moderated the trend of biomass trajectories, with a final exploited biomass relative to the biomass at maximum sustainable yield (B₂₀₁₉/B_msy) for three stocks that exceeded the overfished threshold. This suggested that CMSY may overestimate or underestimate B/B_msy depending on the trend of stock abundance. Overall, independent fishery surveys should be conducted to obtain CPUE and biological data to improve assessment accuracy.