SINGAPORE 



Shrimp are cultivated in rearing ponds. About 1,200 acres 

 are currently under cultivation. The production averages over 1,100 

 pounds per acre per year or a total of over 1,3 million pounds. By 

 utilization of suitable swampy area not presently used, up to ten times 

 this total could be produced. 



Shrimp ponds are constructed by enclosing swampy areas of 

 tidal river basins with a mud dyke fitted with sluice gates. These gates 

 control the flovj of water into or from the ponds. The ponds are filled 

 by the tidal flow and the gates closed until the tide recedes. After a 

 sufficient head of water is obtained, the gates are opened and the water 

 in the pond is allowed to run out through long conical nets fitted to 

 the gates. The shrimp and fish carried by the current are thus filtered 

 out by the net. 



As the tide rises again above the internal level of the pond, 

 the sluice gates are opened to permit the free influx of the tidal flov/ 

 which carries with it shrLmp and fish. At full tide, the gate is closed. 

 The net is again placed in position and the sluice gate opened. 



Most operators work the pond 20 days a month during the period 

 of good tides. The catch generally increases with the spring tides and 

 falls sharply vjith the highest flood. 



The best sites are on lovj--lying flat tidal swamps in mudc^ 

 river basins where the physical contours of the area do not permit an 

 excessive fall in salinity even after heavy rains. A raised area limits 

 the total inflow and, hence, the productivity. 



The shrimp move in the surface waters only at night. It is 

 desirable to let as much v;ater out as possible during the day to permit 

 a good sweep of the current into the pond at night. 



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