Assessment of environmental loads of Cu and Zn from intensive inland shrimp aquaculture.

An experiment was developed to simulate inland shrimp farming using diluted seawater (1.9 g L-1) containing 75 shrimps (Litopenaeus vannamei) per square meter during a growth cycle of 120 days. In this study, the environmental loads of copper and zinc were estimated and compared to anthropogenic sources and shrimp aquacultures in other locations. Both metals resulted primarily from feeding, which accounted for 91.8% of Cu and 97.0% of Zn. Concentrations of Cu (110.8 ± 11.8 μg g-1) and Zn (69.0 ± 0.7 μg g-1) measured in the harvested shrimp had higher Cu and lower Zn concentrations compared to those reported for farmed shrimp from Brazil and Mexico. Clearly, organic sludge was the main route of removal for both metals (Cu 46.2%; Zn 92.6%). The annual environmental loads estimated for inland shrimp aquaculture were 598 ± 74 g Cu ha-1 and 5080 ± 328 g Zn ha-1.