The black kokanee , or " kunimasu " in japanese , was thought to have died out in 1940 , when a hydroelectric project made its native lake in northern akita prefecture more acidic .

黑科卡尼，日语又称“kunimasu”，在1940年就被认为已经灭绝，那时秋田县北部的一个水电项目使得那里的天然湖波水质酸化。