Evaluación de la concentración de amonio y nitrito en el agua de un sistema intensivo de cultivo de camarón

Abstract

Shrimp farming in Ecuador is one of the main important and main non-oil items in export. The intensification of shrimp culture leads to a large load of organic matter and presence of high nitrogenous compounds that affect the system and the quality and health of the shrimp. In the present work, parameters such as ammonium, nitrite, temperature, dissolved oxygen and hydrogen potential were analyzed in 3 semi-intensive shrimp ponds. The water analysis was carried during 53-day at 0.5 ups salinity. In all ponds, ammonium and nitrite increased after reaching day 19 of culture period. The nitrite and ammonium concentrations of the first 19 days do not exceed the values of 0.06 mg/L of ammonium and 0.05 mg/L of nitrite. From day 20 onwards, ammonium values increase from 0.1 to 2.5 mg/L and nitrites from 0.1 to 1.98 mg/L respectively. Dissolved oxygen was always above 4 mg/L. The concentrations of ammonium and nitrite in pond # 1 were between 0.01 to 2.06 mg/L of ammonium and 0.01 to 1.53 mg/L of nitrite with a survival of 72% respectively. The concentrations of ammonium and nitrite in pond #2 were between 0.01 to 2.06 mg/L of ammonium and 0.01 to 1.53 mg/L of nitrite with a survival of 78% respectively. The concentrations of ammonium and nitrite in pond #3 were between 0.01 to 2.06 mg/L of ammonium and 0.01 to 1.53 mg/L of nitrite with a survival of 85% respectively. The variability of ammonium and nitrite concentrations in the water was in order from highest to lowest for ponds 1, 2 and 3 respectively. The temperature in all the tanks fluctuated between 28 to 34 degrees Celsius, which may have affected the physiology of the shrimp on days of high temperatures. The pH remained below 8, which shows that water management was quite acceptable in maintaining this parameter. According to this exploratory study, in intensive L. vannamei shrimp culture systems, the concentrations of ammonium and nitrite in the water tend to increase over time, which could be the cause of moralities.