Características limnológicas da coluna d'água e dos efluentes de viveiros de criação de camarões-da-amazônia

Abstract

The objective of this research was to characterize the effluents of fish ponds of Macrobrachium amazonicum cultured in different densities of farming and to analyze the daily variation (24 hours) of the vertical temperature and oxygen saturation profile of the water column of the ponds. The study was conducted during a period of three months using 12 rectangular 100 m2 earthen ponds supplied with M. amazonicum individuals in four densities of farming (40, 60, 80 and 100 individuals/m2), each one evaluated with three replicates. Follow-up of the daily variation of the temperature and of the saturation of the dissolved oxygen was monthly carried out in the fish ponds (from the surface to the bottom). It was determined, in the effluent caused by the prawn farming, the values of total-N, ammoniacal-N, nitrite-N, nitrate-N, total-P, orthophosphate-P and turbidity. Daily stratifications and desestratifications of temperature and of the saturation oxygen were recorded, irrespective of farming density, characterizing the ponds as a polimitic system of circulation. The higher the density of cultivation of M. amazonicum, the higher the values of total-P, total-N, orthophosphate-P, N-ammoniacal and turbidity. © 2010 Sociedade Brasileira de Zootecnia.