42 December 2011 in the CCP, RCP and PCP, respectively. On the other hand, absolute growth rates and specific growth rates in the three experimental ponds were 0.201 g/day and 1.02 percent /day, 0.205 g/day and 1.03 percent/day, 0.175 g/day and 0.94 percent/day in the CCP, RCP and PCP, respectively. FCR in the CCP, RCP and PCP were 3.24, 3.67 and 1.12, respectively. FCE in the CCP, RCP and PCP were 30.80, 27.23 and 89.20 percent, respectively (Figures 2-5). Conclusion Research findings from the present study suggest that the present level of coastal shrimp culture practice no longer risks exceeding environmental capacity of the system with respect to nutrient loading. The present status of nutrient concentrations associated with shrimp farms has been reduced and the aquatic environment is able to accommodate the present level of aquaculture production. It was found that nutrient enrichment was very poor in a PCP. It was also found that the production of shrimp was very low in PCP than the other two ponds. So, farmers must stop reusing water for shrimp culture and shrimp pond waste should be Table 4. Water volumes and flushing rates in the study area. Water volumes Types Area ( m2) percent area Water volume ( m3) Canal area 226721 7 percent 680163 Non-production area 607049 19 percent Pond area 2387730 74 percent 3581595 Total 3238866 100 percent 4261758 Flushing rates Types of pond Frequency/ Percent/ Volume/ Water Flushing month time pond (m3 ) exchange ( m3) rate (percent) Canal connected pond 8 10 percent 1351698 1081358.4 80 River connected pond 8 12 percent 1630131.60 1564926.3 96 Pond connecting pond 6 10 percent 342780.90 205668 60 Fig. 2. Variation of TN (mg/L) in CCP. Fig. 3. Variation of TN (mg/L) in RCP. Fig. 4. Variation of TN (mg/L) in PCP. (Continued from page 40)
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