Cultured species of aquatic animals span more than five phyla. Animal welfare attention is directed towards the vertebrates because of the their neural complexity, and is currently focused on the finfish because of the size and visibility of that segment of the aquaculture industry. The characteristics of the aquatic environment and their impact on the animal have forced growers to develop cultural practices designed to control and minimize animal stress. This was not done as a result of social awareness, but out of necessity to keep fish alive and healthy; and managing stress is a principal key in ensuring animal welfare. Aquatic farmers are aware of the consequences of fish stress, but have limited knowledge of the basic biological principles of animal stress and have little exposure to the linkages between these concepts and the issues critical to animal welfare. Although the industry has many tools available for monitoring and preventing stress, not all growers have had exposure to the information that is available or know of its value when addressing issues of animal welfare.