基于广义可加模型分析时空和环境因子对2013年南极磷虾资源分布的影响

摘要

根据2013年1—9月南极磷虾拖网调查数据，以单位捕捞努力量渔获量作为资源密度指标，分析南极磷虾资源空间分布特征和月间变化。结果表明，1—6月的月均单位捕捞努力量渔获量值相对稳定，7—9月逐月下降。渔区的平均单位捕捞努力量渔获量值以48．1小区最高，为（25．12±31．04） t／h，48．3小区最低，为（11．49±12．06）t／h；单位捕捞努力量渔获量值的波动幅度48．1小区大于48.2小区和48．3小区。广义可加模型筛选出的解释变量对南极磷虾空间分布的影响由大到小依次为：月份、经度、拖网深度、水深、纬度和表层水温。各因子的偏差解释率分别为16．82％、11．17％、3.98％、1．75％、1．54％和0．88％，所有因子对单位捕捞努力量渔获量的总偏差解释率为36．14％。本次调查的结果可为研究南极磷虾渔场形成机制和渔业管理提供参考。%According to the data of Antarctic krill (Euphausia superba) trawl survey from January to September in 2013 ,the temporal and spatial distribution of Antarctic krill resources were analyzed with the index of CPUE .The results showed that monthly average catch per unit effort (CPUE) was relatively stable from January to June ,but declined after July .The maximum(25 .12 ± 31 .04) t/h average CPUE was observed in subarea 48 .1 ,and the minimum (11 .49 ± 12 .06) t/h in subarea 48 .3;whereas ,the change in net CPUE was greater in subarea 48 .1 than in 48 .2 and 48 .3 .The results of stepwise GAM showed that the important explanatory variables affecting the spatial distribution of Antarctic krill were month ,longitude ,trawling depth ,sea bottom depth ,latitude and surface sea temperature (SST) ,and the deviance explanation by these explanatory variables was accounted for 36 .14% in total .