基于渔业调查的利文斯顿岛西南部2012年秋冬季南极大磷虾体长时空分布

基于南极磷虾渔业科学观察员收集的南极大磷虾(Euphausia superba)体长数据,将研究区域划分成经纬度10'×10'小尺度单元,分析了利文斯顿岛西南部水域2012年秋冬季南极大磷虾体长分布的时空特征。结果表明,10个单元的平均体长范围为35.3～51.0 mm,其中最小体长为23.1 mm,最大体长为61.0 mm,各单元间体长分布存在显著性差异。由秋末转至冬初,南极大磷虾平均体长及优势体长范围均呈逐渐减小趋势。14～16时和22～24时南极大磷虾个体较小,而4～6时、8～10时以及20～22时的南极大磷虾则以大个体为主。一半以上(72%)的样本分布于40～80 m水层。80 m以深水层,南极大磷虾个体均大于38 mm。随着海区水深的增加,南极大磷虾平均体长逐渐减小,且南极大磷虾体长组成在不同水深海区呈现不同的分布模式。

The temporal-spatial distribution of standard length for Euphausia superba in the southwestern Livingston Island in the austral fall-winter 2012 based on fishery survey

Based on the length data of Euphausia superba Dana collected by the Antarctic krill fishery observers,the study analyzed the spatial-temporal distribution of standard length for Antarctic krill in the southwestern Livingston Island in the austral fall-winter 2012 by dividing the study area into 10 small-scale units with 10′ latitude and 10′ longitude.The results showed that: the range of average length was 35.3 to 51.0 mm in the 10 units,the minimum and the maximum length was 23.1 mm and 61.0 mm,respectively.Significant differences could be found among the units for the length distribution.The average standard length and the dominant range of standard length were decreasing gradually.The smaller individuals were caught in 14 to 16 o′ clock and 22 to 24 o′ clock,but the larger could be found in 4 to 6,8 to 10 and 20 to 22 o′ clock.Over half samples(72%) were distributed in the layer 40 to 80 m under the surface.The standard length of Antarctic krill was below 38 mm when the layer was 80 m under the surface.The average standard length was decreasing with the increase of the water depth and different distribution patterns of standard length could be found in the area with different water depths.