Natural mortality estimation and rational exploitation of purpleback flying squid Sthenoteuthis oualaniensis in the southern South China Sea  

作　　者：王雪辉 邱永松 张鹏 杜飞雁 

机构地区：[1]Guangdong Provincial Key Laboratory of Fishery Ecology and Environment,South China Sea Fisheries Research Institute,Chinese Academy of Fishery Sciences

出　　处：《Chinese Journal of Oceanology and Limnology》2017年第4期902-911,共10页中国海洋湖沼学报（英文版）

基　　金：Supported by the National Key Technology R&D Program(No.2013BAD13B06);the Guangdong Provincial Program of Science and Technology(No.2014A020217011);funded by the State Oceanic Administration(No.GASI-02-SCS-YSW);supported by a Special Fund for Youth Training from the South China Sea Fisheries Research Institute

摘　　要：Based on the biological data of purpleback flying squid(Sthenoteuthis oualaniensis)collected by light falling-net in the southern South China Sea(SCS) during September to October 2012 and March to April 2013,growth and mortality of 'Medium' and 'Dwarf' forms of squid are derived using the Powell-Wetherall,ELEFAN methods and length-converted catch curves(FiSAT package).Given a lack of commercial exploitation,we assume total mortality to be due entirely to natural mortality.We estimate these squid have fast growth,with growth coefficients(k) ranging from 1.42 to 2.39,and high natural mortality(M),with estimates ranging from 1.61 to 2.92.To sustainably exploit these squid stocks,yield per recruitment based on growth and natural mortality was determined using the Beverton-Holt dynamic pool model.We demonstrate squid stocks could sustain high fishing mortality and low ages at first capture,with an optimal fishing mortality >3.0,with the optimal age at first capture increased to 0.4-0.6 years when fishing mortality approached optimal levels.On the basis of our analyses and estimates of stock biomass,we believe considerable potential exists to expand the squid fishery into the open SCS,relieving fishing pressure on coastal waters.Based on the biological data of purpleback flying squid （Sthenoteuthis oualaniensis） collected by light falling-net in the southern South China Sea （SCS） during September to October 2012 and March to April 2013, growth and mortality of ＇Medium＇ and ＇Dwarf＇ forms of squid are derived using the Powell-Wetherall, ELEFAN methods and length-converted catch curves （FiSAT package）. Given a lack of commercial exploitation, we assume total mortality to be due entirely to natural mortality. We estimate these squid have fast growth, with growth coefficients （k） ranging from 1.42 to 2.39, and high natural mortality （M）, with estimates ranging from 1.61 to 2.92. To sustainably exploit these squid stocks, yield per recruitment based on growth and natural mortality was determined using the Beverton-Holt dynamic pool model. We demonstrate squid stocks could sustain high fishing mortality and low ages at first capture, with an optimal fishing mortality 〉3.0, with the optimal age at first capture increased to 0.4-0.6 years when fishing mortality approached optimal levels. On the basis of our analyses and estimates of stock biomass, we believe considerable potential exists to expand the squid fishery into the open SCS, relieving fishing pressure on coastal waters.

关 键 词：purpleback flying squid Sthenoteuthis oualaniensis mortality dynamic pool model FISHERY South China Sea 

分 类 号：S917.4[农业科学—水产科学]