In conclusion, the development of veterinary externships at a marine laboratory in conjunction with veterinary schools was an extremely useful training mechanism. The losses of fish to diseases and environmental conditions can be reduced by reduction or elimination of diseases in the freshwater phase of culture, avoiding the transfer of infected brood stock to the freshwater site, use of appropriate vaccines, use of chemotherapeutants where appropriate, and improved management of stock density, handling, and feeding in seawater. Further studies are needed on conditions such as toxic hepatopathy, algal toxins, and algae producing toxic effects in fish. Studies are needed to develop a vaccine for the prevention of ulcerative stomatitis. Bacterial kidney disease free stocks of fish would further increase productivity. Surveillance of fish health in both freshwater and seawater is needed as well as management of smolt quality. Many of these recommendations for improvements have been implemented since this study was completed resulting in greatly increased productivity of fish farming in Puget Sound, Washington.