In recent years, sweetfish that don't descend to the sea but instead overwinter in dams and lakes can be seen here and there throughout Japan. These are the ones that spend their entire lives in freshwater only, using lakes and dams as substitutes for the sea. For several years now, young sweetfish caught at Agi River Dam have been released into neighboring rivers. Sweetfish are precious! Their ability to adapt to their environment is wonderful.
Sweetfish have been living in the Japanese archipelago - or rather, in this area - for millions of years. Their roots are far more ancient than us Japanese people...