捕捞数据不确定下蓝点马鲛渔业管理策略评估

Management strategy evaluation of mackerel(Scomberomorus niphonius) fishery with uncertainty of catch data

蓝点马鲛是黄渤海的主要经济鱼种,在我国海洋渔业中占有重要地位,评估其资源水平和种群状态对于资源开发和管理具有重要意义。传统的渔业资源评估方法对数据有较高的要求,而目前我国蓝点马鲛渔业缺乏相关数据,特别是捕捞统计数据存在的问题尤为明显,其平均水平和变化趋势均存在很大的不确定性,统计上表现为观测数据的误差和偏差,对渔业评估和管理造成了障碍。本研究采用输出控制和输入控制两类共6种基于有限数据的渔业管理规程(MP)对蓝点马鲛进行了资源评估,针对捕捞观测数据的误差和偏差对这6种MP进行了不确定分析和管理策略评价。结果显示,输出控制MP中稳定捕捞法(CC4)、最大可持续剩余产量捕捞趋势法(SPMSY)和平均渔获量法(AvC)受到渔获量观测偏差和误差不同程度的影响,而时滞差分资源评估法(DD)对渔获量的不确定性响应相对较弱,更适用于蓝点马鲛等渔获量数据不确定性较大的渔业。根据敏感性分析发现该类MP对最大可持续生物量与未开发的生物量的比值、补充关系的陡度、最大可持续捕捞死亡率与自然死亡率的比值以及最大可持续捕捞死亡率等参数均较为敏感。而输入控制类MP最小体长法(minlen Lopt1)及75%捕捞努力量法(cur E75)对渔获量的不确定性响应不明显,对操控模型中各参数敏感程度较低。本研究指出输入控制MP不易受到观测误差和观测偏差的影响,而输出控制MP对观测误差有不同程度的响应。本研究使用管理策略评估综合比较两类MP,认为cur E75对于渔业资源的开发和保护两个方面有着最好的权衡。

Spanish mackerel is an economic species in the Yellow Sea and Bohai Sea, which occupies an important position in marine fishery, and it is important to evaluate its biomass and stock status. However, the fishery lacks relevant data in China, which causes the difficulty in fisheries evaluation and management. Among them, the uncertainty of catch data is especially noticeable, and its variation in values and trends is often measured with the observation error and bias. This study evaluated the performances of six data-limited management procedures which belong to two categories： output control and input control, and we focus on their response and sensitivity to observation error and bias of catch data. Our results indicate that output control MPs including CC4 SPMSY and Av C are more sensitive to observation error and bias, while DD showed slight response to observation error and bias, which is more suitable for managing mackerel fishery. And the sensitivity analysis showed that output control MPs are sensitive to the OM parameters including BMSY/B_0, hs, FMSY/M and FMSY. Relatively, the input control including minlen Lopt1 and cur E75 is not sensitive to the uncertainty of catch data and OM parameters. In general, we can conclude that the input control MP shows minor responses to the catch error and catch bias, whereas the output control MP shows different responses to the catch error. And according to the MSE, cur E75 has the best balance between the exploitation and protection of mackerel fishery.