The results are presented of studying icefish vertical migration based on the data of R/V cruises during the seasons of 1982-83, 1983-84 and 1986-87, when this species was highly abundant on the South Georgia shelf. It is revealed that at day time the fish distributes near the bottom and the maximum catches were available at the middle of the light hours of the day. At twilight the fish concentrations migrate into the water column and the catches greatly decrease. The direct observations of icefish vertical migrations provided by means of hydroacoustic equipment are presented.
There is no abstract available for this document.
There is no abstract available for this document.
There is no abstract available for this document.
There is no abstract available for this document.
There is no abstract available for this document.
There is no abstract available for this document.
There is no abstract available for this document.
There is no abstract available for this document.
Abstract:
Method of estimation of krill drift velocity in water current,using repeated acoustic transects on rectangular polygon is discribed.Dimensions of polygon and frequency of acoustic observations have to be determined with taking into account distribution patterns of krill,its patchiness, between-swarm distance (BSD) and between-clusters distance (BCD).For ocean current velocity- 20 sm/sec,ship speed-8 knots,mean BSD-5km,mean BCD-6.3 km dimensions of polygon must be 10 12 km and discretness of acoustic transects 4 hours.
