Hatchery Programs of Chum Salmon in Hokkaido, Japan: Current Perspectives and Issues

In Japan, chum salmon Oncorhynchus keta stocks are managed by hatchery programs that constitute one of the largest hatchery programs in the world. The programs are successful for the purpose of increasing commercial catches in Hokkaido, northern Japan, and are currently conducted by non-profit salmon enhancement program associations. At present, there is no evidence of any decrease of genetic diversity in chum salmon in Japan despite the intensive hatchery programs. However, there are several other problems; e.g., a distinct difference in return rates has emerged among regions, early-runs have been increased but late-runs have decreased, and transplants of eggs and juveniles are conducted. Hatchery programs should be the main management tool for chum salmon in the future because commercial fisheries cannot be sustained without hatchery programs in the narrow land area of Japan. It is hoped that researches on naturally spawning chum salmon will be advanced and novel management policies will be considered to restore naturally spawning salmon populations. After understanding the specific situations of fisheries management in Japan, scientific consideration of future management of chum salmon should be advanced, diffused and agreed by fishermen and hatchery managers.