基于丰度指数和恢复力的渔业资源评估:以日本海和东海带鱼为例

Fish stock assessment based on abundance index and resilience:a case study of largehead hairtail in Sea of Japan and East China Sea

为了解日本海和东海带鱼(Trichiurus japonicus)渔业资源状况,利用一种基于丰度指数的评估模型(Abundance maximum sustainable yields,AMSY)对2个海域的带鱼资源进行了评估。结果显示,2个海域的带鱼渔业在20世纪90年代至21世纪00年代的大部分时间里相对资源量水平(B/BMSY)低于1,而相对捕捞死亡水平(F/FMSY)高于1,处于过度捕捞状态。AMSY模型里相对最大可持续产量(MSYq)和MSY水平下的捕捞死亡系数(FMSY)等参数评估结果对不同内禀增长率(r)先验分布范围比较敏感,而B/BMSY和F/FMSY等生物学参考点评估结果对特定年份的相对资源量水平(Bt/k)先验分布范围的下限设置比较敏感。AMSY模型仅需要单位捕捞努力量渔获量(Catch per unit effort,CPUE)数据、评估对象的r和特定年份的Bt/k水平先验信息,可以评估基于MSY的生物学参考点(B/BMSY和F/FMSY),适合无统计产量数据的海域内渔业资源评估。

In order to understand the exploitation status of largehead hairtail(Trichiurus japonicus)fisheries in the Sea of Ja-pan and the East China Sea,we used a fishery assessment model based on abundance index(Abundance maximum sustainable yields,AMSY)to assess the two fisheries.The results show that during most of the 1990s and 2000s,the relative biomass levels(B/BMSY)of the largehead hairtail fisheries in the two seas were lower than 1,but the relative fishing mortality levels(F/FMSY)were higher than 1,which indicates an overfished state.The estimated parameters such as relative maximum sustainable yield(MSYq)and relative fishing mortality at MSY level(FMSY)of the AMSY model were more sensitive to different prior distribution ranges of intrinsic rate of increase(r),while the estimated biological reference points(BRPs),i.e.,F/FMSY and B/BMSY were more sensitive to the lower limit of different prior distribution ranges of relative biomass level(Bt/k).AMSY can estimate the BRPs of the target fisheries under MSY framework using only catch per unit effort(CPUE)data,prior information of r and relative bio-mass level for a specific year.AMSY is appropriate for fishery stock assessment in the sea areas where lack statistical data of catches.