Water reuse in an integrated system with shrimps, sedimentation, oysters and marine macroalgae

Abstract

Aquaculture got an important world-wide development in the last decades, but the intensification of this activity resulted in negative ambient impacts mainly generated by culture effluents which contain high dissolved nutrients concentrations. The aim of this work was to analyze water quality in an integrated aquaculture system, composed by shrimps (Litopenaeus vannamei (Boone, 1931)), sedimentation, oysters (Crassostrea rhyzophorae (Guilding, 1828) ) and marine macroalgae (Amansia multifida (Lamouroux, 1809) and Gracilaria cervicornis (Turner) J. Agardh, 1852) ), using ammonia concentrations and turbidity as control parameters. Two four aquariums trials had been used and each one was composed of an aquarium for shrimp culture, other destined to remaining portions of ration and dregs sedimentation, other for oyster’s culture and a last one for macroalgae culture. Daily, the water was manually moved, passing from an aquarium to another. The oysters showed excellent filtration ability during all the experiment, significantly reducing ammonia and turbidity high levels of the sedimentation water. Macroalgae had also been efficient in reducing the ammonia concentrations and practically without modifying the turbidity values. The establishment of this integrated system made possible the use of the same water during a four months period. Water quality improvement carried through oysters and algae resulted in an excellent L. vannamei shrimp growth. Thus, the use of integrated aquaculture systems can be a good tool to mitigate intensive shrimp culture ambient impacts.