Possible approach to krill movement estimation by hydroacoustic observations

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.