Dynamic model of dissolved oxygen in intensive concrete pond of white leg shrimp (Litopenaeus vannamei) in Bomo Village, East Java

This study is to understand a simple model of dissolved oxygen (DO) and other water quality factors that affect it in two seasons in intensive white leg shrimp ponds. Water quality parameters in the dry and rainy seasons in several ponds were sampled daily, including temperature, pH, (DO), salinity, twice a week, including ammonium, nitrite, nitrate, orthophosphate, total alkalinity, and total bacteria. Besides daily, dissolved oxygen is also measured before the harvest every two hours by using dark bottles and light bottles. Pond water quality parameters are still suitable for white shrimp culture. Daily DO shrimp ponds form a polynomial regression model. DO in light bottles constructed a quadratic regression model, DO in dark bottles created a linear regression pattern, with a DO reduction rate of 0.6338 mg-l per hour. During one of the shrimp cultures, the DO model showed an inverse quadratic equation with the lowest oxygen solubility level on day 57. DO was positively correlated with changes in salinity and transparency and negatively related to ammonium, nitrate, phosphate, total alkalinity, and total bacteria count.