Influence of diet and feeding strategy on the performance of nitrifying trickling filter, oxygen consumption and ammonia excretion of gilthead sea bream (Sparus aurata) raised in recirculating aquaculture systems

Abstract Gilthead sea bream ( Sparus aurata ) was raised in six individual recirculating aquaculture systems (RAS) whose biofilters’ performance analyzed. Fish were fed with three different diets (a control diet, a fishmeal-based diet (FM), and plant meal-based (VM)) feeding strategies (manual to apparent satiation, automatic restricted ration, auto-demand feeding). For every combination of strategy, the mean oxygen consumption, ammonia excretion, removal rate determined. VM consumed most (20.06 ± 1.80 gO 2 kg ?1 day ). There significant differences excretion depending on protein content efficiency as well which turn affected rates. by feeders led highest (0.10 gN-TAN removed m ?2 biofiltration area ), while not leading peaks high concentration water, preserve fish welfare growth.