摘要
根据1982—2014年33年的长江口汛期凤鲚(Coilia mystus)捕捞数据,采用多元统计分析研究凤鲚捕捞量的年际变化,利用格局转变贯序t检验(sequential t-test testing analysis of regime shifts,STARS)的方法研究捕捞量年际转变规律,并结合广义可加模型(generalized additive model,GAM)定量分析了凤鲚捕捞量与捕捞船数及环境因子长江口水温、泥沙量和径流量的相关性。结果显示,1982—2014年长江口凤鲚汛期总捕捞量和单船全汛捕捞量变幅分别为7.9~3252.0 t·年^-1和130.0~12945.5 kg·年^-1,总体都呈波动下降趋势。总捕捞量在1997年和2007年发生2次格局转变,年际格局转变指数RSI值分别为-0.580和-0.405;单船全汛捕捞量在1990年和2007年发生格局转变,RSI值分别为-0.806和-0.371。捕捞船数变幅为59~330艘·年^-1,分别在1990年、2000年和2006年发生3次年际格局转变,对应RSI值分别为0.992、-0.412和-0.763。通过对环境因素与捕捞因素的分析发现,凤鲚单船全汛捕捞量发生第一次格局转变主要受过度捕捞因素的影响,而第二次发生转变主要受环境和捕捞因素的共同影响。GAM模型结果揭示,输沙量与凤鲚单船全汛捕捞量呈正相关关系,表现为随着输沙量的增加,单船全汛捕捞量随之增加;反之,水温与单船全汛捕捞量呈负相关关系,即随着水温升高,单船全汛捕捞量随之降低。
Based on the long-term fishing data series of Coilia mystus collected from the Yangtze River Estuary for 33 years from 1982 to 2014,multivariate statistical analysis was used to study the interannual variations of catches of C.mystus.Regime shift indexes(RSIs)of long-term fishing data series were calculated by sequential t-test analysis of regime shifts(STARS)to examine and identify the extent and timing of regime shifts in C.mystus catches.In addition,to examine the interannual variations of C.mystus catches in the Yangtze River Estuary and its relationship with environmental factors,we gathered long-term environmental data series,including local surface water temperature,sediment discharge and water discharge,and analyzed the data using generalized additive model(GAM)and regime shift.The main objective was to facilitate the understanding of interannual variations of C.mystus catches in the Yangtze River Estuary and the effects of various environmental factors on C.mystus catches,to provide basic research data for the conservation and sustainable use of C.mystus resources.Results indicated that the annual fishing boat numbers in the Yangtze River Estuary fluctuated greatly,varied from 59 to 330 boats·a^-1 and showed an increasing trend from 1982 to 1989,followed by a decreasing trend in 1990.There were three regime shifts of fishing boat numbers in 1990,2000 and 2006,with RSI values of 0.992,-0.412 and-0.763.The total annual catches ranged from 7.9 to 3252.0 t·a^-1 and CPUE ranged from 130.0 to 12945.5 kg·a^-1,and the overall data all showed a fluctuating downward trend.Sequential t-test testing analysis of regime shifts indexes showed that there were two regime shifts of total catch in 1997 and 2007,with RSIs of-0.580 and-0.405 respectively.And there were also two regime shifts of CPUE in 1990 and 2007,with RSIs of-0.806 and-0.371 respectively,indicating a steep decline in CPUE.Through the analysis of environmental variables and fishing factors,it was found that the first regime shift in CPUE of C.mystus possibly coupled to overfishing,while the second regime shift in CPUE of C.mystus was mainly affected by the combined effects of environmental and fishing factors.The generalized additive models(GAM)indicated that annual changes in C.mystus CPUE were partially affected by local surface water temperature and sediment discharge.The sediment discharge showed a positive relationship with CPUE,CPUE increased with the increasing sediment discharge.However,the surface water temperature was negatively correlated with CPUE,and CPUE was reduced as the water temperature increased.
作者
倪健夫
郭弘艺
唐文乔
张亚
张旭光
NI Jian-fu;GUO Hong-yi;TANG Wen-qiao;ZHANG Ya;ZHANG Xu-guang(Key Laboratory of Marine Animal Taxonomy and Evolution, Shanghai Ocean University, Shanghai 201306, China;International Research Center for Marine Biosciences, Ministry of Science and Technology, Shanghai Ocean University, Shanghai 201306, China;National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai 201306, China)
出处
《海洋渔业》
CSCD
北大核心
2020年第2期192-204,共13页
Marine Fisheries
基金
2018年国家重点研发计划“蓝色粮仓科技创新”(2018YFD0900800)
上海高校实验技术队伍建设项目(A1-2007-00-000602)。
关键词
长江口
广义可加模型
凤鲚
格局转变
Yangtze River Estuary
generalized additive models
Coilia mystus
regime shift
