基于GAM模型的南海鸢乌贼CPUE时空分布及其与环境因子的关系

Effects of spatiotemporal and environmental factors on the fishing ground of Sthenoteuthis oualaniensis in the South China Sea based on the Generalized Additive Model

根据2013—2016年南海两艘灯光罩网渔船的生产统计资料,结合卫星遥感获取的环境因子数据,运用广义可加模型(GAM)分析了南海春季鸢乌贼渔场分布及其与时空和环境因子的关系。结果表明:2013—2014年鸢乌贼单位捕捞努力量渔获量(CPUE,Catch Per Unit Effort)呈增长趋势,而2015—2016年CPUE明显下降。2013—2015年鸢乌贼中心渔场主要分布在114°E—115°E,10°N—12°N区域,而2016年中心渔场向西偏移;GAM模型对CPUE的总偏差解释率为66.40%,其中经度、纬度、海表温度和叶绿素浓度4个因子与CPUE显著相关(P<0.05),影响因子按重要性排列,从大到小依次为:经度、纬度、叶绿素浓度和海表温度。而年份、月份和海表盐度对CPUE影响不显著(P>0.05)。鸢乌贼适宜海表温度为27℃~30℃,适宜叶绿素浓度为0.10~0.15 mg/m^(3)。

Based on light falling-net fishery production data from 2 vessels collected from 2013 to 2016 in the South China Sea,and the satellite data of environmental factors,the fishing ground distribution of Sthenoteuthis oualaniensis and its relationships with the spatiotemporal and environmental factorsin the South China Sea is studied using Generalized Additive Model(GAM).The results suggest that the Catch Per Unit Effort(CPUE)of S.oualaniensis in 2013-2014 shows an increasing trend,while significantly declining in 2015-2016.The fishing ground of S.oualaniensis in the South China Sea was mainly located in the waters of[114°E-115°E,10°N-12°N]in 2013-2015,and turned west in 2016.GAM model shows that the rate of the cumulative deviance explained about CPUE is 66.40%.Four factors,including longitude,latitude,sea surface temperature(SST)and chlorophyll-a concentration(CHL),have significant effects on the CPUE(P<0.05),the relative importance of them inaffecting the fishing ground of S.oualaniensis can be followed the order of longitude,latitude,CHL and SST.Other factors,such as year,month and sea surface salinity(SSS)do not have significant effects on the CPUE(P>0.05).The optimal environment for S.oualaniensisisunder conditions of 27℃~30℃SST and the CHL of 0.10~0.15 mg/m^(3).