studies on improved practices of prawn farming for higher ...

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tides. Farmers build embankments to a height half way between the high
and low tides and then construct a fence on top of the embankment to
enclose the sfinimp. Other farmers use typical sei-intensive ponds
that are completely enclosed with embankments. The warm climate in
Japan permits year round production.
Korea
Based on Japanese methods, the artificial culture of the shrimp
E, orientalis has been achieved in Korea on a commercial scale. But no
detailed report about these operations is so far available.
Malaysia
The method of shrimp culture in Malaysia (Hall, 1962; Tham,
1968) differs from Philippines in that the young shrimps are not
stocked in the ponds artificially by operators, but brought in
naturally by tidal flow. lhufli of the swampy brackishwater areas are
utilised as shrimp ponds. By partially clearing some of the vegetative
growths and erecting mud walls with suitably sited sluice gates, the
swamps are converted into shrimp ponds varying in sizes from less than
5 to 50 acres in extent. The incoing tidal waters are let into the
ponds through the sluice gates twice a day and let off' with the
receding tides maintaining a water level of at least 60 cm inside the
pond. The depth of the pond is not uniform, average mean high tide
depth being about 120 cm. The sluices are about 1.2 m wide. They are
lined along the sides and bottan with wooden boards. Planks of wood
sliding vertically in slots are used as shutters for regulating the
flow of tidal water in and out of the ponds. The shutters are operated
by a wooden hand windlass. Fishing operations are conducted during
low tide by placing a net attached to a wooden frame against the
outflowing water at the sluice gate during nights. A wooden race way
is provided cni the outerside of the sluice gate so that the net does
not get torn as the current rushes through it. The net is emptied at
the cod end.