Automatic feeding and Harvesting of Juvenile Atlantic Cod (Gadus Morhua L.) in a Pond

Abstract

Abstract Large scale production of juvenile Atlantic cod has been carried out since 1980 in a saltwater pond. A break-through was obtained in 1983 with high survival rates of cod larvae to metamorphosis, in 1985 we made progress within two fields: reduced cannibalism and automatic harvesting. Juvenile cod formed large schools while fed dry pellets in the currents set up by five propellers. An underwater loudspeaker was programmed to give sound pulses just before feeding. During harvesting dry pellets were released inside a fish trap while giving the sound signals the cod juveniles were conditioned to. The cod readily entered the trap and a computer-controlled fish pump transported the fish from the fish trap into a storing tank and grading grids. The trap gradually emptied the pond for fish and more than 80% or 100.000 juvenile cods were captured with the automatic harvesting system.