Reduction of Colloidal Particles In Intensive Rearing of Cod Larvae (Gadus morhua) In Recirculating Aquaculture System (RAS) Applying a Membrane Bioreactor (MBR)

摘要

As the world population is increasing, there is an increased demand for food, and aquaculture is the fastest expanding segment of agriculture. There is a growing interest for recirculating aquaculture systems (RAS) for cultivation of live feed, larvae and fry, and on-growing fish. In RAS more than 90% of the water is being recycled back to the rearing tanks after treatment. By applying RAS it is possible to conserve heat and water, eliminate escapement of farmed fish to the natural habitat, reduce the loads of biosolids and sludge deposits to the surrounding water area, and control the bacterial population by microbial maturation of the water. A stable concentration of substrate is a selective force to trigger water maturation and growth of a slow growing beneficial bacterial community. Most diseases of marine fish larvae are suggested to be caused by opportunistic microorganisms that become pathogenic when the fish larvae are under stressed conditions.