"Extinct" Salmon Discovered in Japanese LakeFinding the fish was "was incredible, unbelievable," expert says. A Japanese salmon thought to have been extinct for 70 years has been discovered in a lake near Mount Fuji. The kunimasu salmon, also called the black kokanee, is a subspecies of sockeye salmon that's found only in Japan. Unlike true sockeye, which migrate between freshwater and the oceans,