2010/2011年夏季南设得兰群岛北部水域南极磷虾的种群组成

Population composition of Antarctic krill(Euphausia superba) in the northern South Shetlands Island areas during the austral summer of 2010/2011 season

为了解中国南极磷虾渔业主要渔场——南设得兰群岛水域南极磷虾种群动态,利用渔业科学观察员收集的生物学数据,在将研究区域划分成10'×10'小尺度单元的基础上,实验分析了南设得兰群岛夏季南极磷虾种群组成的时空特征。结果表明,23个单元中,雌性未成体(F2)的比例最高(42.1%),其次为雌性成体(F3,35.6%),雄性个体所占比例不足20%,且均为未成体(M2),而幼体(I1)的比例仅占2.7%。12月中旬,I1阶段的磷虾个体占有一定的比例(9.6%),M2阶段磷虾个体比例较F3阶段高。12月下旬的情况与1月上旬较为相似,I1个体未出现在调查样本中,M2阶段磷虾个体比例下降,F3阶段磷虾个体比例明显上升。M2、F2和F3阶段的磷虾个体在各水层中的分布模式较为相似(PSI=90.9～97.7)。I1阶段磷虾个体主要分布在60～80 m水层(66.9%),而其它3个性成熟度的磷虾个体主要分布在40～60 m水层。

In order to understand the population dynamics of Antarctic krill（Euphausia superba Dana）in the South Shetland Islands,the main Chinese fishing ground of Antarctic krill fishery,using the biological data collected by the fishery observers,the present study analyzes the spatial-temporal characteristics of population composition of Antarctic krill based on dividing the study area into small scale units with the latitude-longitude spatial resolution of 10′ and 10′.The results show that,in the 23 units analyzed,the proportion of immature females is highest（42.1%）,followed by mature females（35.6%）,the proportion of males is below 20% and all individuals are immature,the proportion of juvenile individuals is only 2.7%.Compared with other periods,the individuals in juvenile stage is higher（9.6%）in the middle of December 2010 and the proportion of immature males（M2）is higher than that of mature females（F3）.The similarity of maturity stage composition can be found in the last ten-day period of December 2010 and the first ten-day of January 2011,the juveniles can not be found in the samples and the proportion of M2 is decreasing and the proportion of F3 is significantly increasing.The distribution patterns of M2,F2 and F3 are similar in the different water layers（PSI=90.9-97.7）.The juveniles are mainly distributed in the 60 to 80 m layer（66.9%）and the individuals of F2,M2 and F3 are located in the 40 to 60 m layer.