In 1877, Japan received its first shipment of rainbow trout from California, according to Japan's National Institute for Environmental Studies (NIES). The fish, also known in some areas as steelhead, were deliberately introduced for food and sport fishing. At the time, the introduction seemed practical. Rainbow trout are favored by both fish farmers and anglers for their fast growth, good taste, and strong fight on a line.
Rainbow trout are native to the Pacific coast from Kamchatka, Russia, and Alaska to Baja California. The species prefers clean, well-oxygenated water, usually in fast-flowing streams, but some populations also establish in lakes and reservoirs. Some of the trout stocked in Japanese fish farms eventually escaped into nearby rivers. They didn't just survive in the wild once they were free; they started competing with fish that had lived in the rivers of Japan for thousands of years.
