Dissolved Oxygen Budget for Pacific White Shrimp (Litopenaeus vannamei) Culture in Earthen Ponds

Abstract

Dissolved oxygen (DO) is one of the important factors which affect the quantity and quality of Pacifi c white shrimp (Litopenaeus vannamei) grown under intensive culture in earthen ponds. The aim of this research was to develop a model of the dissolved oxygen budget for shrimp culture for 5 mth during May to September 2009 (the fi rst month for water preparation, the other months for nurture). The method was based on the conservation of mass. Empirical experiments were used to consider: 1) water oxygen production, 2) aeration by paddle wheel and 3) oxygen uptake in sediment, shrimps and water. The oxygen uptake in sediment increased each month, with a range of 0.03–0.11 mg.L-1.hr-1. The oxygen production and oxygen consumption by water were highest in the third month, and decreased in the fourth and fi fth months, with a range of 0.13–0.51 and 0.06–0.33 mg.L-1.hr-1, respectively. Oxygen consumption by shrimps in the 2nd, 3rd, 4th, and 5th months was 0.04, 0.06, 0.17 and 0.19 mg.L-1.hr-1, respectively, and the average wet weight of shrimps was 1.8 ± 0.8, 6.8 ± 0.8, 15.8 ± 1.3 and 21.2 ± 1.3 g, respectively. The aeration rate by a paddle wheel was in the range 0.1–0.3 mg.L-1.hr-1. When all parameters were applied in the model, the predicted DO agreed with the observed DO with a correlation coeffi cient value of 0.9, which indicates that the assumption inherent in the DO budget processes was valid for the DO production and consumption in the pond.