北部湾二长棘犁齿鲷时空分布及其与环境因子的关系

Spatiotemporal Distribution of Threadfin Porgy Evynnis cardinalis in Beibu Gulf and Its Relationship with Environmental Factors

【目的】研究北部湾二长棘犁齿鲷资源密度时空分布与海洋环境因子的关系,为二长棘犁齿鲷资源利用和保护提供理论基础。【方法】基于2013年11月至2014年8月4个航次的北部湾渔业资源调查航次数据,利用广义可加模型(Generalized Additive Model,GAM)研究二长棘犁齿鲷与遥感海表水温(SST)、叶绿素a浓度(Chl-a)、海表面异常(SLA)和水深等海洋环境因子,以及经纬度等空间因子的关系,利用渔场重心分析资源分布及迁移特征。【结果与结论】北部湾二长棘犁齿鲷资源密度春夏季高于秋冬季,以春季最高。GAM模型对资源密度偏差的总解释率为51.6%,影响资源密度最重要的因子为SST,贡献率为25.9%,其次为纬度、SLA和Chl-a,贡献率分别为11.3%、9.4%和5.0%。二长棘犁齿鲷资源密度分布重心为季节性移动,秋季到冬春季从北部湾西南海域向北部湾东北部海域迁移,夏季向西南方向折返。

【Objective】To study the relationship between spatiotemporal distribution of threadfin porgy Evynnis cardinalis and marine environmental factors,and to provide important information for the optimal utilization and conservation of fishery stock in the Beibu Gulf.【Method】The generalized additive models(GAMs)analysis was performed using the stock density data from four seasonal otter trawl surveys conducted between November,2013 and August,2014,remote sensing data of environmental factors,including sea surface temperature(SST),chlorophyll-a concentration(Chl-a),and sea level anomaly(SLA),and the spatial factors,including latitude(Lat),longitude(Lon)and water depth.Analysis of central fishing-ground gravity(CFGG)was also conducted to indicate its shifting characteristics.【Result and Conclusion】The stock density of E.cardinalis is higher in spring and summer than that in autumn and winter,while the density in the spring is the highest.GAMs analysis results showed that the total explained deviation of stock density was 51.6%,in which the most important factor was SST,with a contribution of 25.9%,followed by Lat,SLA and Chl-a,with contributions of 11.3%,9.4%and 5.0%,respectively.CFGG analysis showed that E.cardinalis shifted seasonally in the Beibu Gulf,from southwest coastal area in autumn,to the northeastern coastal area in winter and spring,and then turned southwestward in the summer.