Japan's Herring Hatcheries

摘要

Uniquely, Japan has developed hatcheries to enhance diminish wild herring stocks.In 1982 efforts began in Hokkaido, Japan to develop a herring nursery production program for resource enhancement. The program was managed by the Japan Aquaculture Association. Successful, current techniques produce 1 million or more herring with a 40%survival rate for release, and have contributed gready to adult harvests since the onset of the program.The enhancement centers around four distinct ecotypes in Japan that lead to distinct herring populations: lake and marsh regions (fish spawning in low salinity water); oceanic region (coastal spawning and fry development); widely dispersed oceanic region(the most abundant, spawning in coastal areas, large migration, late maturation); and intermediate regions (spawning in low salinity water, with long migration). A significant feature of local herring populations is that they exhibit a homing pattern for spawning.