Implications of uncertainty in the spawner-recruitment relationship for fisheries management: An illustration using bigeye tuna (Thunnus obesus) in the eastern Pacific Ocean
详细信息查看全文 | 推荐本文 |
摘要
The impacts of the steepness parameter of the Beverton-Holt spawner-recruitment curve on fisheries stock assessment and management performance were evaluated, using data for bigeye tuna (Thunnus obesus) in the eastern Pacific Ocean. The analysis was conducted using the Stock Synthesis model. The estimates of maximum sustainable yield (MSY) and related management reference points are sensitive to the value of steepness (ranging from 0.4 to 1.0) of the Beverton-Holt spawner-recruitment relationship assumed in the assessment model. Steepness also impacts the evaluation of stock status. A lesser value assumed for steepness leads to a more pessimistic evaluation of the stock status regarding whether the stock is overfished or overfishing is occurring. However, a lesser value does not reduce the estimates of MSY due to the interaction between steepness and the estimates of other model parameters. When managing the stock under effort limitation using MSY-based fishing mortality, a lower assumption of steepness yields less expected losses in catch than does a higher assumption. This is due to the flatness of the yield curve when the steepness is high. A lower assumption of steepness also maintains a higher level of spawning biomass and recruitment.

© 2004-2018 中国地质图书馆版权所有 京ICP备05064691号 京公网安备11010802017129号

地址:北京市海淀区学院路29号 邮编:100083

电话:办公室:(+86 10)66554848;文献借阅、咨询服务、科技查新:66554700