广东海洋渔业资源可捕量评估

Assessment of allowable catches of fishery resources in Guangdong waters

为探明广东省海洋渔业资源现状及其对实现渔业可持续发展的重要意义,基于广东省1961—2018年海洋渔业统计产量数据,利用一种包含协变量的剩余产量模型(a surplus-production model incorporating covariates,ASPIC)和Catch-MSY模型对广东海洋渔业资源总可捕量、5个重要经济类群的最大可持续产量(maximum sustainable yield,MSY)以及可捕量进行了评估。结果显示,ASPIC与Catch-MSY模型的评估结果相近,广东海洋渔业资源MSY约为164×10^(4) t,1996—2006年处于过度捕捞状态,当前产量低于MSY。Schaefer与Fox模型评估的MSY相差不大,且B/B MSY与F/F_(MSY)的历史变化趋势较为一致,但是评估的渔业现状差异较大,Schaefer模型评估结果表明当前渔业状态较差(B/B MSY<1且F/F_(MSY)>1),而Fox模型表明当前渔业状态良好(B/B MSY>1且F/F_(MSY)<1)。综合两个模型结果显示,带鱼类MSY为14.62×10^(4)~15.08×10^(4) t,日本鲭(Scomber japonicus)MSY为3.82×10^(4)~6.78×10^(4) t,鲳类MSY为5.77×10^(4)~6.21×10^(4) t,鲷类MSY为4.16×10^(4)~4.54×10^(4) t,蓝圆鲹(Decapterus maruadsi)MSY为17.68×10^(4)~19.84×10^(4) t。5个经济类群中日本鲭和蓝圆鲹处于过度捕捞后的衰退状态,而带鱼类、鲳类和鲷类在近年来遭受过度捕捞。研究结果可为广东海洋渔业限额捕捞提供理论依据。

Guangdong Province is a major marine fishery province in China.It is of great significance to estimate the present status of fishery resources for the sustainable development.However,due to limited funding and data for such surveys,only 1%of fish stocks have undergone systematic assessments.Therefore,it is difficult to assess the maximum sustainable yield(MSY)or determine allowable catch for most fishery resources using traditional methods.Catch-MSY model is a simplified model that needs balance hypothesis to combine yield data,resilience information and resource quantity level.ASPIC(a surplus-production model incorporating covariates)software can fit the residual yield model well without balancing assumptions.Based on statistics data of catches and fishing efforts during 1961—2018,Catch-MSY model and ASPIC program were used to estimate the allowable catches and the maximum sustainable yield(MSY)for five commercial fish groups and total allowable catch(TAC)in Guangdong Province.Results showed that the estimated MSYs of Guangdong waters by ASPIC program and Catch-MSY model were similar at 164×10^(4) t.Although fishery resources have been overfished from 1996 to 2006,the total catch in 2018 was 127×10^(4) t and less than MSY.The MSY results of Schaefer model and Fox model were also similar,and the historical trends of B/B MSY and F/F_(MSY) were relatively consistent.However,there was an obvious difference in estimating current fishery status between Schaefer model and Fox model.Schaefer model showed that the current fishery state was poor,byt Fox model showed that the current fishery state was good.The evaluation result curve of Guangdong marine fishery CPUE was flat and decreasing,and the fitting result of Fox model was closer to the real CPUE than that of Schaefer model.The data of five economic groups produced multiple outliers in the Fox model,so the evaluation results of Schaefer model and Catch-MSY model were used.Results of Catch-MSY model and ASPIC showed that MSY of cutlassfishes fishery was 14.62×10^(4)-15.08×10^(4) t,3.82×10^(4)-6.78×10^(4) t for Scomber japonicus fisheries,5.77×10^(4)-6.21×10^(4) t for butterfishes,4.16×10^(4)-4.54×10^(4) t for porgies,and 17.68×10^(4)-19.84×10^(4) t for Decapterus maruadsi fishery.The Scomber japonicus and Decapterus maruadsi fisheries have been recovering after collapse,and the stocks of cutlassfishes,butterfishes and porgies have also been overfished in recent years.This study used two methods to estimate the total allowable catch of Guangdong marine fishery resources and the MSY and allowable catch of five important economic groups,and compared the difference of evaluation results under CPUE data.The research results can provide technical support for Guangdong marine fishery quota fishing and total management.