南极普里兹湾外海大磷虾声学映像的分布分析和生物量的初步估算

本文主要根据 1 990 /1 991年度中国南极考察队南大洋调查所获的探鱼仪的磷虾映像资料 ,经 WT- 2图像处理系统处理分析 ,结果表明 ,1 990 /1 991年度南极夏季 ,普里兹湾外海域 (6 2°- 6 9°S,6 8°- 1 0 8°E)的磷虾主要分布在 6 1°- 6 5°S,1 0 3°- 1 0 8°E海区 ,该海区的探鱼仪记录的磷虾群映像的面积占整个调查海区的 92 .3 2 %,磷虾群的分布水层主要在 3 0 - 6 0 m水层 ,在一天 2 4小时中 ,磷虾群映像面积的形心基本在 40 m层上下起伏 ,波动幅度约 1 0 m左右。在调查海区 (6 2°- 6 9°S,6 8°- 1 0 8°E)内 ,估算磷虾资源现存量为 2 2 0 0万吨 ,磷虾分布密度平均为 3 2 .5 t/km2。

DISTRIBUTION AND A PRILIMINARY OBSERVATION OF THE BIOMASS OF ANTARCTIC KRILL IN THE PRYDZ BAY REGION BY ECHOGRAM ANALYSIS

Surveys on ocean environment,particularly on krill ecology,were carried out twice in the Prydz Bay area by the Sixth and Seventh Antarctic Explorations during the 1989/1990 and 1990/1991 Antarctic summer.A colour fishfinder Atlas 792 DS made in Germary was used to search Antarctic krill in the whole course.On the basis of the images recorded by the fishfinder and the results obtained from sampling stations,the concentration of krill off the Prydz Bay area was very scarce in 1989/1990.According to the images obtained from the investigation of an area of 6.75×10 5km 2 off the Prydz Bay area (62°-69°S,68°-108°E) conducted by the Seventh Antarctic Exploration from 27th Dec.,1990 to 11th Jan.,1991 and the analyses of the distribution of krill in the surveyed areas,the results show that the horizontal distribution of krill in the surveyed waters can be divided into three areas(i.e.61°-65°S,103°-108°E;63°30′-64°30′S,84°-86°E;62°-65°S,72°-73E°);most of the krill aggregation were in depth of 30-60m and the central area of krill concentration undulated in the layer of 40 meters in 24 hours a day,with about 10 meters in range of fluctuation. Also according to the image records from the Seventh Antarctic Exploration and aimed fishing sampling of krill by IKMT(Isaus-Kidd Midwater Trawl),2.2×10 8 tons of standing crops and 32.59 t/km 2 of density of distribution were hydroacoustically estimated using WT-2 type of image processing system and special software.