Salmon Species
Hokkaido is world-famous for its salmon. Three types of salmon are commonly found around Kushiro: chum salmon (Oncorhynchus keta), pink salmon (O. gorbuscha), and masu salmon (O. masou).
Chum salmon, the predominant salmon species in the seas around Kushiro, is best known for its large orange roe. After chum salmon migrate and mature in the Sea of Okhotsk, the North Pacific, and the Bering Sea for around four years, they return to their home grounds to spawn once before they die. More than 100,000 salmon migrate up the Kushiro River between September and December each year. Since 1876, breeding programs have helped maintain a healthy population.
Pink salmon, the most abundant species of salmon in the world, inhabit the Pacific Ocean and the Sea of Okhotsk. In Hokkaido, pink salmon spawn in rivers along the east coast from Kushiro to Shiretoko. During the spawning season, the males develop a humped back and larger teeth to help them fight off rival males as they battle to fertilize eggs released by the females.
Masu salmon live half their lives in rivers and half in the ocean, then return to their home river to spawn before dying. They have a limited range, staying in coastal waters off northern Japan after reaching maturity.