Naas has worked as a scientist at the Institute of Marine Research from 1985 to 1996. His field of research was related to marine fish larval ecology, with emphasis on behavioral responses to light and turbidity. He was central in development of rearing techniques for juveniles, both by extensive and intensive methods. In 1996 he left the academic career and started a commercial hatchery for Atlantic halibut. He also worked some years as a consultant in marine aquaculture before he took the position in The Research Council of Norway (RCN). From 2010 he has coordinated the Aquaculture program in the RCN.