Culture of cobia Rachycentron canadum in a recirculation aquaculture system in northern Chile

Abstract

An innovative aquaculture project involving the thermal seawater effluent of a thermoelectric power plant and a recirculating aquaculture system (RAS) was implemented in the Atacama Desert, the driest in the world located in northern Chile to produce the warm water pelagic fish cobia ( Rachycentron canadum Linnaeus, 1766). An experimental land-based fish farm was built consisting of nine independent RAS provided with adequate temperature (28°C) and salinity (32) for cobia growth and overall aquaculture performance. Under these conditions, cobia was raised from egg to an average weight of 4 ± 0.4 kg in 12 months. Growth rates were similarly high for all the batches, and mortalities from weaning up to harvest sizes never exceeded 6%. Besides, no antibiotics were ever used, and no infectious diseases ever detected during the four years experimental phase reported herein. The batches of eggs arrived in Chile in 2012 and 2014. After three years, 12 t of cobia were consistently produced per every eight months’ cycle. During this period, successful reproduction and routine volitional spawning of broodstock were achieved, producing offspring from F1 and F2 generations. The biological potential and economic feasibility of the RAS concept for raising cobia in temperate, desert regions was demonstrated and is described. Farm management, multi-trophic aquaculture, animal welfare, proactive health management, zero water effluent discharge, and total recycling of wastes are also discussed as a means of expanding the concept into a commercial phase.