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Submitted to: Aquaculture Research
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 11/25/2007 Publication Date: 12/13/2007 Citation: Green, B.W. 2007. Stocking strategies for production of Litopenaeus vannamei (Boone) in amended freshwater in inland ponds. Aquaculture Research. 39:10-17. Interpretive Summary: The Pacific white shrimp Litopenaeus vannamei is being cultured far from coastal areas in ponds filled with low-salinity ground water or brine transported from the coast and diluted on site with freshwater. The quantity of ions in low-salinity ground water often differs from quantities found in dilute seawater at the same salinity, and this ionic imbalance can affect survival of shrimp grown in the low-salinity ground water. Shrimp survival and production can be improved by adding mineral supplements to the low-salinity ground water. Since the ionic composition of low-salinity ground water can be corrected by mineral addition, it should be possible to add minerals to freshwater for its use in growing marine shrimp in ponds at inland sites. Ponds in Arkansas were filled with freshwater and supplemented with the major ions found in seawater to attain a salinity of 0.7 parts per thousand and were stocked with young Pacific white shrimp. Shrimp production was comparable to that obtained by coastal farmers and the individual size at harvest was acceptable for US markets. These experiments demonstrated that this marine shrimp can be grown successfully in ponds filled with freshwater and supplemented with the major ions found in seawater. This information will allow inland fish farmers to diversify their production strategies. Technical Abstract: The performance of the Pacific white shrimp Litopenaeus vannamei (Boone) under various stocking strategies was evaluated in earthen ponds filled with freshwater amended with major ions. Six 0.1-ha earthen ponds located in Pine Bluff, Arkansas, USA, were filled with freshwater in 2003 and 2004, and potassium magnesium sulfate added to provide 50 mg K+ L-1 and stock salt added to provide 0.5 g L-1 salinity. In 2003, three ponds either were stocked with PL15 shrimp (39 PL m-2) for 125 d of grow out or with PL25 shrimp for a 55-d (23 PL m-2) followed by a 65-d (28 PL m-2) grow-out period. In 2004, ponds were stocked with 7, 13, or 30 PL15 m-2 for 134 d of grow out. Salinity averaged 0.7 g L-1 during both years, and concentration of SO4-2, K+, Ca2+, and Mg2+ was higher, and Na+ and Cl- was lower in amended pond water than in seawater at 0.7 g L-1 salinity. Potassium concentration in amended water was 52-61% of the target concentration. Shrimp yields ranged from 3,449 kg ha-1 in 2003 to 4,966 kg ha-1 in 2004 in ponds stocked with 30-39 PL15 m-2 for a 125-134-d culture period. At harvest, mean individual weight ranged from 17.1-19.3 g shrimp-1. In ponds stocked with PL25 shrimp, yields averaged 988 and 2,462 kg ha-1 for the 1st and 2nd grow out periods, respectively. Gross shrimp yield in 2004 increased linearly from 1,379 – 4,966 kg ha-1 with increased stocking rate. These experiments demonstrated that L. vannamei can be grown successfully in freshwater supplemented with major ions to a final salinity of 0.7 g L-1. |
