| Summary: | Progress Code: completed Statement: Krill/Zooplankton/Fish: Net Sampling Regular trawl stations were laid out approximately every second CTD stations. Target trawls were undertaken whenever any target of interest were detected on the echosounder. Single opening-closing RMT 1+8 net (Baker et al., 1973) with CTD System installed was used for all of the tows (Regular and Target), Hard cod-ends were used for all the trawls. Flow meters were used to estimate the volume of water towed. Table 1 summarises the details of RMT stations. Ringnet deployments were undertaken at almost every CTD stations. Regular Trawl At each regular trawl station a quantitative standard double oblique tow was conducted from the surface down to 200 m (or to within 10 m of the bottom at stations shallower than 200 m). Such a depth range is considered to be the best compromise between the time available for sampling and the likely vertical depth range of krill. During the hauls, ship's speed was maintained constant at 2.5 plus or minus 0.5 knots. Wire speed of 0.7 to 0.8 m/s during paying out and of 0.3 m/sec during hauling(approx. 0.5 m/s and 0.2 m/s respectively at vertical depth change rate). The net mouth angle is remarkably constant during hauling within the speed ranges given above. When the net reaches maximum depth, the winch was stopped for about 30 seconds to allow the net to stabilise before retrieving. When hauling, the propeller thrust was turned off when the net reached depth of 15 to 20 m; this was to minimise the effects of the propeller action on the net operation and avoid damage of the samples. Target Trawl Whenever interesting targets were seen on the echo-sounder, or large amount of krill was required for any purpose, target trawls were performed. Once the position of the target was marked, the ship was turned and navigated to run over the target from direction required within navigation capacity. The ship speed was reduced to below 2.0 knots before hitting the target, so that the net could be lowered down to the desired ...
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