Production and welfare of trout in a recirculation system versus conventional aeration

Abstract

To evaluate two hydraulic detention times in a recirculation aquaculture system (RAS) versus the conventional aeration and their effect on productive variables (weight gain, final stocking density, and specific growth rate) and animal welfare (erosion of dorsal, pectoral and caudal fin) of rainbow trout. Trout with a stocking density of 10 kg/m3 were cultured in a RAS consisting of a constant water level box, suction tank, two culture units, upflow anoxic digester, aerobic three phase fluidized bed reactor with concentric pipes, pre and post filtration systems, compressor, blower, UV sterilization filter, and two electric pumps. The RAS culture tanks had hydraulic detention times of one hour (T1) and 0.5 hours (T2), the conventional aeration, isolated from the RAS had no water exchanges (T0). There were no statistically significant differences between T1 and T2 treatments, which reported higher weight gain, final stocking density, and specific growth rate values than the T0. The survival rates for T1 and T2 were 100%, and 8.13% for T0, fin erosion was observed mainly in T1 and T2, caused by high densities. The RAS demonstrated a good capacity for trout culture by water reuse and pollutant load reduction. © 2016, Fundacion CIPAV. All rights reserved.