03.08.2013 Views

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

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

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

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

18<br />

et al., 1964). The bheries are chiefly large pereminal water bodies<br />

surrounded by earthern dykes which are c<strong>on</strong>structed by borrowing earth<br />

fro the trenches excavated inside the bheries near the toe line <strong>of</strong> the<br />

dykes. The bheries are deeper and larger in extent than the pokkali<br />

fields <strong>of</strong> Kerala. Usually the bheries have single sluice which serves<br />

both the purpose <strong>of</strong> taking the tidal water during spring tide and<br />

releasing water from bheri during ebb tide. The producti<strong>on</strong> system in<br />

bheries is largely based <strong>on</strong> trapping holding and culture <strong>of</strong> wild seeds<br />

<strong>of</strong> shrimps and fishes taken during high tide. Prawns are obtained<br />

al<strong>on</strong>g with the mullets and perches. The stocking is d<strong>on</strong>e during<br />

January-February and fishing is carried out in September-Decanber.<br />

During the 10 m<strong>on</strong>ths, fishes are inside the impoundments and feed <strong>on</strong><br />

the natural food provided by the habitat which gets replenished by the<br />

animal and plant life c<strong>on</strong>tained in the incoming tide waters. These<br />

farms are known to yield 168-672 kg/ha <strong>of</strong> shrimp and fish and hold<br />

l.ITlIl'l€l'1S€ potential <strong>of</strong> development. This traditi<strong>on</strong>al practice is giving<br />

way to selective stocking with desirable culture species <strong>of</strong> <strong>prawn</strong>s and<br />

fishes (Natarajan, 1985).<br />

During scientific preparati<strong>on</strong> <strong>of</strong> the field, care is given to<br />

provide canals <strong>of</strong> various dimensi<strong>on</strong>s occupying about 8% area to hold<br />

the fish in extreme situati<strong>on</strong>s. The height <strong>of</strong> dykes normally varied<br />

from 1.5 m to 1.8 m and the crest width is kept at 60 cm. Two tier<br />

system <strong>of</strong> sluices are also fixed suitably. From March <strong>on</strong>wards tidal<br />

water is drawn into the field which brings in the seeds <strong>of</strong> commercial<br />

species <strong>of</strong> <strong>prawn</strong>s and fishes. This will be c<strong>on</strong>tinued upto June with<br />

all earlier precauti<strong>on</strong>s taken not to inundate the paddy beds with<br />

saline tidal water. With the <strong>on</strong>set <strong>of</strong> m<strong>on</strong>so<strong>on</strong>, the entry <strong>of</strong> tidal<br />

water is stopped and the fishes harvested when an yield <strong>of</strong> 200-400<br />

kg/ha/4 m<strong>on</strong>ths is obtained.<br />

The m<strong>on</strong>so<strong>on</strong> showers thoroughly wash the paddy beds which also<br />

raises the water level in fields. At this time required cuttings are<br />

made in the dykes to permit the free flow <strong>of</strong> water. In due course<br />

c<strong>on</strong>genial ecological c<strong>on</strong>diti<strong>on</strong>s are restored in the field when Kharif

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!