This system should be operated on a non-profit basis and supported by the public. Through this arrangement, artificial propagation could be promoted as well as the preservation of natural stocks through negotiation with industries. In the United States, resources of salmonid fish are maintained primarily by natural reproduction. Natural environments suitable for their reproduction are scientifically studied and investigated. Research on the fresh water environment and ecological system have been done for a long time.
Sport fishing plays a vital role in resource management.
In contrast, in Japan research is focused on the technology of artificial propagation. There has been little study of the environment or the ecology of freshwater systems. Also, minimal attention has focused on developing a resource management system for salmon. In Japan, the condition of the rivers is very different from the United States. Research on the freshwater environment and ecological system should be urged.