1999/2000年夏季南极普里兹湾地区南极磷虾的分布、丰度和生长状态研究

1999 2 0 0 0年的南极夏季 ,在普里兹湾地区进行了南极磷虾 (Euphausiasuperba)的现场采样。采样站位共 1 5个 ,分布在由近岸到深海的三条经向断面上。采样中在 1 4个站位都有南极磷虾出现 ,但大多数站位磷虾的密度都很低。样品的组成主要是幼体后期的南极磷虾。整个调查海区南极磷虾的平均数值密度和重量密度分别为 1 6 .1 7尾 1 0 0 0m3 和 1 2 .0 2g 1 0 0 0m3 。在调查区域内除密度最大的站位在深海区外 ,其他密度较大的站位主要分布于陆坡区 ,而在陆架区的唯一的站位没有发现南极磷虾。测量和分析的结果表明 ,陆坡区南极磷虾的生长状态好于深海区 ,但就整个调查海区来说 ,南极磷虾处于正常生长状态。对调查期间普里兹湾的环境因素的分析结果表明 ,调查中三个磷虾密度较大的站位 (Ⅱ - 3 ,Ⅲ - 6 ,Ⅳ - 8)的分布似乎与 75m深处的冷水团及 2 5m深处的叶绿素低值中心和叶绿素高值中心的交汇区有关。

DISTRIBUTION,ABUNDANCE AND GROWING CONDITION OF THE ANTARCTIC KRILL(EUPHAUSIA SUPERBA) IN 1999/2000 IN THE PRYDZ BAY REGION,ANTARCTICA

Antarctic Krill ( Euphausia superba ) were collected from the Prydz Bay region during the austral summer of 1999/2000. Three longitudinal transects,with 15 sites,were sampled. Although krill were encountered in 14 sites,the densities were comparatively low in general. The main component of the krill population was post larval stages. The mean numerical density and weight density integrated for the whole survey region were 16.17 ind./1000 m 3 and 12.02 g/1000 m 3,respectively. The abundance of krill was relatively high and they distributed more evenly in slope area than the open sea area,except that the highest value was found in open sea area. No krill occurred in the only station of the shelf area. The krill were growing better in the slope area than in the open sea area,but as for the whole study area,Antarctic krill were under normal growing state. The results of the analyses of the environmental factors indicate the presence of the three large sample stations were to some extent related to the cold water mass at 75 m depth,as well as the confluence area between the high and low Chl a centers at 25 m depth.