中东大西洋中部海域鲐鱼渔场的时空变化初步研究

Spatial-temporal Patterns in Fishing Ground of Scomber japonicus in Central Eastern Central Atlantic Ocean

根据2012年1—8月中国大型拖网渔船在中东大西洋中部海域联合国粮食与农业组织34渔区3.11和1.32小区(北纬16°~22°,西经16°~19°)的鲐鱼渔业数据以及遥感获取的海洋环境数据,利用渔获量重心法、地统计插值、广义加性模型等方法,对该海域中层拖网鲐鱼平均单位捕捞努力量渔获量的月变化、鲐鱼中心渔场的时空变动、鲐鱼渔场中心与环境因子(叶绿素a含量与海表温度)的分布、鲐鱼单位捕捞努力量渔获量与各影响因子(海表温度、叶绿素a含量、经度、纬度)的关系进行了分析。结果表明,该海域各月鲐鱼平均单位捕捞努力量渔获量基本呈现先减少后增加的趋势;鲐鱼中心渔场的分布具有明显的月变化,基本呈现先往东南方向推移,且在4月份到达最东南端,然后往西北推移趋势;不同月份渔场中心叶绿素a含量为0~10mg/m3,且渔场中心叶绿素a含量为3~8mg/m3居多。不同月份渔场中心的海表温度为17.3~27.6℃,且渔场中心的海表温度为20~21℃居多。广义加性模型模型分析表明,鲐鱼渔场的最适海表温度为19~22℃,最适叶绿素a含量为4.481~7.388mg/m3,经度集中在西经16°30′附近,纬度集中在北纬18°30′位置附近。海洋环境与鲐鱼单位捕捞努力量渔获的回归方程的显著性检验表明,海表温度、叶绿素a含量和经度在单位捕捞努力量渔获量上的回归均极显著(P<0.01)且显著性强弱顺序依次为海表温度、经度和叶绿素a含量,而纬度在单位捕捞努力量渔获量上的回归不显著(P>0.05)。中东大西洋中部海域联合国粮食与农业组织34渔区3.11和1.32小区鲐鱼渔场的时空变化与几内亚湾暖流、加那利寒流等洋流不同月份的强弱变化关系密切。本研究得出的渔场最适海表温度和最适叶绿素a含量可以作为预报该海域潜在鲐鱼渔场的指标之一。

The monthly changes in mean catch per unit effort（CPUE）of Scomber japonicus,Spatio-temporal change in S.japonicus central fishing ground,Stack distribution of S.japonicus central fishing ground and environmental factors including chlorophyll a concentration and sea surface temperature（SST）,and the relationships between S.japonicus CPUE and affecting factors including SST,chlorophyll a concentration,longitude and latitude were analyzed by aproduction-centered method,statistical interpolation,mathematical statistics,a Generalized additive models（GAM）model and other methods based on the fishery data of S.japonicusin the sea area of subdivision 3.11 and 1.32 of FAO Fishing Area 34（W16°—19°,N 16°—22°）in central Eastern Central Atlantic Ocean in Chinese vessels from January to August,2012 as well as marine environmental data obtained by remote sensing.The results showed that the average CPUE was decreased firstly,and then increased in different months,that spatio-temporal changes in central fishing ground with monthly variation,The central fishing ground reached extreme southeast on April,went to southeast firstly,and then to northwest.Chlorophyll a mass concentration in fishing centers in different months was ranged from 0 mg/m^3 to 10 mg/m^3,most in 3—8 mg/m^3.SST in fishing centers was 17.3—27.6℃ in different months,mosth 20—21℃.GAM model analysis revealed that the optimum SST of S.japonicus fishing ground was 19—22 ℃,the optimum chlorophyll a mass concentration of 4.481—7.388 mg/m^3,longitude concentrated around 16°30＇,and latitude concentrated around 18°30＇.Regression analysis between CPUE and marine environmental data revealed that the correlations between SST,chlorophyll a concentration and longitude and the CPUE were highly significant,with the order of SST longitude chlorophyll a concentration,without significance in latitud.Changes in the strength of the warm Gulf of Guinea,the Canary cold ocean currents and the Spatial-temporal variation of S.japonicus central fishing ground in the sea area of subdivision 3.11 and 1.32 in FAO Fishing Area 34 of central Eastern Central Atlantic were closely related.The optimum SST and the optimum chlorophyll a concentration in fishing ground in the study can be used as one of index of forecasting potential fishing zone.