Based on catch and effort data of tuna longline fishery operating in the South Pacific Ocean, the South Pacific albacore stock was assessed by an improved Schaefer model. The results revealed that the intrinsic growth...Based on catch and effort data of tuna longline fishery operating in the South Pacific Ocean, the South Pacific albacore stock was assessed by an improved Schaefer model. The results revealed that the intrinsic growth rate was about 1.283 74 and carrying capacities vareied in the range from 73 734 to 266 732 metric tons. The growth ability of this species is remarkable. Stock dynamics mainly depends on environmental conditions. The stock is still in good condition. However, the continuous decreasing of biomass in recent years should be noticed.展开更多
秋刀鱼(Cololabis saira)是西北太平洋温带海域的主要捕捞对象之一,也是西北太平洋渔业重要的组成部分。本研究根据北太平洋渔业委员会(NPFC)统计的2003~2017年渔获量数据以及中国秋刀鱼组织提交的单位捕捞努力渔获量数据(Catch per uni...秋刀鱼(Cololabis saira)是西北太平洋温带海域的主要捕捞对象之一,也是西北太平洋渔业重要的组成部分。本研究根据北太平洋渔业委员会(NPFC)统计的2003~2017年渔获量数据以及中国秋刀鱼组织提交的单位捕捞努力渔获量数据(Catch per unit effort, CPUE),基于贝叶斯Schaefer剩余产量模型,分基准方案和敏感性分析方案对西北太平洋秋刀鱼资源状况进行了评估,并对其管理策略做了风险分析。结果显示,基准方案和敏感性分析方案下模型参数预测值以及生物学参考点估计值比较相近。在基准方案下,估算的最大可持续产量(Maximum sustainable yield,MSY)为75.26×10^4 t,最大可持续产量的资源量BMSY为240.14×10^4 t,此时的捕捞死亡率为0.32。在敏感性分析方案下,估算的最大的可持续产量MSY为70.03×10^4t,最大可持续产量的资源量BMSY为232.53×10^4t,此时的捕捞死亡率为0.31。该海域秋刀鱼资源状况良好,未经受过度捕捞。风险评估分析表明,为使秋刀鱼资源可持续利用,需将捕获率设定在0.3左右。展开更多
The southern Patagonian stock（SPS） of Argentinian shortfin squid, Illex argentinus, is an economically important squid fishery in the Southwest Atlantic. Environmental conditions in the region play an important role...The southern Patagonian stock（SPS） of Argentinian shortfin squid, Illex argentinus, is an economically important squid fishery in the Southwest Atlantic. Environmental conditions in the region play an important role in regulating the population dynamics of the I. argentinus population. This study develops an environmentally dependent surplus production（EDSP） model to evaluate the stock abundance of I. argentines during the period of 2000 to 2010. The environmental factors（favorable spawning habitat areas with sea surface temperature of 16–18°C） were assumed to be closely associated with carrying capacity（K） in the EDSP model. Deviance Information Criterion（DIC） values suggest that the estimated EDSP model with environmental factors fits the data better than a Schaefer surplus model without environmental factors under uniform and normal scenarios.The EDSP model estimated a maximum sustainable yield（MSY） from 351 600 t to 685 100 t and a biomass from 1 322 400 t to1 803 000 t. The fishing mortality coefficient of I. argentinus from 2000 to 2010 was smaller than the values of F（0.1） and F（MSY）. Furthermore, the time series biomass plot of I. argentinus from 2000 to 2010 shows that the biomass of I.argentinus and this fishery were in a good state and not presently experiencing overfishing. This study suggests that the environmental conditions of the habitat should be considered within squid stock assessment and management.展开更多
Small-scale fisheries,particularly those targeting small pelagic fish,are a vital sector in Liberia,providing essential food for the local population and generating income for livelihoods.Sardinella maderensis,predomi...Small-scale fisheries,particularly those targeting small pelagic fish,are a vital sector in Liberia,providing essential food for the local population and generating income for livelihoods.Sardinella maderensis,predominantly caught by motorized canoes using gill nets and seine nets,is the primary species in these fisheries.To establish management target reference points for the S.maderensis fishery,this study applied the Schaefer production model to aggregated and disaggregated catch and effort data collected by Liberia's National Fisheries and Aquaculture Authority(NaFAA)from 2018 to 2022.The findings indicate that,in both the aggregated and disaggregated models,the current(2022)fishing effort exceeds the MEY level,leading to diminishing economic returns and approaching economic overfishing thresholds.The economic reference points,MEY and EMEY,were estimated to be 3%and 19%lower in the aggregated model,and 30%and 44%lower in the disaggregated model,compared to the current(2022)catch and relative fishing effort.This situation arises when the cost of fishing exceeds the price of fish,driven by inefficient and ineffective fishing boats,which leads to high unit costs of effort compared to unit revenue.To fully realize the potential of the S.maderensis fishery,this study recommends a combination of input and output control management strategies,the adoption of more efficient fishing technologies,and the provision of alternative livelihoods for coastal communities.展开更多
文摘Based on catch and effort data of tuna longline fishery operating in the South Pacific Ocean, the South Pacific albacore stock was assessed by an improved Schaefer model. The results revealed that the intrinsic growth rate was about 1.283 74 and carrying capacities vareied in the range from 73 734 to 266 732 metric tons. The growth ability of this species is remarkable. Stock dynamics mainly depends on environmental conditions. The stock is still in good condition. However, the continuous decreasing of biomass in recent years should be noticed.
文摘秋刀鱼(Cololabis saira)是西北太平洋温带海域的主要捕捞对象之一,也是西北太平洋渔业重要的组成部分。本研究根据北太平洋渔业委员会(NPFC)统计的2003~2017年渔获量数据以及中国秋刀鱼组织提交的单位捕捞努力渔获量数据(Catch per unit effort, CPUE),基于贝叶斯Schaefer剩余产量模型,分基准方案和敏感性分析方案对西北太平洋秋刀鱼资源状况进行了评估,并对其管理策略做了风险分析。结果显示,基准方案和敏感性分析方案下模型参数预测值以及生物学参考点估计值比较相近。在基准方案下,估算的最大可持续产量(Maximum sustainable yield,MSY)为75.26×10^4 t,最大可持续产量的资源量BMSY为240.14×10^4 t,此时的捕捞死亡率为0.32。在敏感性分析方案下,估算的最大的可持续产量MSY为70.03×10^4t,最大可持续产量的资源量BMSY为232.53×10^4t,此时的捕捞死亡率为0.31。该海域秋刀鱼资源状况良好,未经受过度捕捞。风险评估分析表明,为使秋刀鱼资源可持续利用,需将捕获率设定在0.3左右。
基金The National Natural Science Foundation of China under contract No.NSFC31702343the Science Foundation of Shanghai under contract No.13ZR1419700+4 种基金the Innovation Program of Shanghai Municipal Education Commission under contract No.13YZ091the National High-tech R&D Program of China(863 Program)under contract No.2012AA092303the Funding Program for Outstanding Dissertations in Shanghai Ocean Universitythe Funding Scheme for Training Young Teachers in Shanghai Colleges and the Shanghai Leading Academic Discipline Project(Fisheries Discipline)Involvement of Chen Yong was supported by SHOU International Center for Marine Studies and Shanghai 1000 Talent Program
文摘The southern Patagonian stock（SPS） of Argentinian shortfin squid, Illex argentinus, is an economically important squid fishery in the Southwest Atlantic. Environmental conditions in the region play an important role in regulating the population dynamics of the I. argentinus population. This study develops an environmentally dependent surplus production（EDSP） model to evaluate the stock abundance of I. argentines during the period of 2000 to 2010. The environmental factors（favorable spawning habitat areas with sea surface temperature of 16–18°C） were assumed to be closely associated with carrying capacity（K） in the EDSP model. Deviance Information Criterion（DIC） values suggest that the estimated EDSP model with environmental factors fits the data better than a Schaefer surplus model without environmental factors under uniform and normal scenarios.The EDSP model estimated a maximum sustainable yield（MSY） from 351 600 t to 685 100 t and a biomass from 1 322 400 t to1 803 000 t. The fishing mortality coefficient of I. argentinus from 2000 to 2010 was smaller than the values of F（0.1） and F（MSY）. Furthermore, the time series biomass plot of I. argentinus from 2000 to 2010 shows that the biomass of I.argentinus and this fishery were in a good state and not presently experiencing overfishing. This study suggests that the environmental conditions of the habitat should be considered within squid stock assessment and management.
文摘Small-scale fisheries,particularly those targeting small pelagic fish,are a vital sector in Liberia,providing essential food for the local population and generating income for livelihoods.Sardinella maderensis,predominantly caught by motorized canoes using gill nets and seine nets,is the primary species in these fisheries.To establish management target reference points for the S.maderensis fishery,this study applied the Schaefer production model to aggregated and disaggregated catch and effort data collected by Liberia's National Fisheries and Aquaculture Authority(NaFAA)from 2018 to 2022.The findings indicate that,in both the aggregated and disaggregated models,the current(2022)fishing effort exceeds the MEY level,leading to diminishing economic returns and approaching economic overfishing thresholds.The economic reference points,MEY and EMEY,were estimated to be 3%and 19%lower in the aggregated model,and 30%and 44%lower in the disaggregated model,compared to the current(2022)catch and relative fishing effort.This situation arises when the cost of fishing exceeds the price of fish,driven by inefficient and ineffective fishing boats,which leads to high unit costs of effort compared to unit revenue.To fully realize the potential of the S.maderensis fishery,this study recommends a combination of input and output control management strategies,the adoption of more efficient fishing technologies,and the provision of alternative livelihoods for coastal communities.
