Kunimasu
Image: Wikimedia Commons
In the 1940s, a hydroelectric dam in Japan’s Lake Tazawako made the water more acidic and wiped out the highly-sensitive kunimasu salmon that lived only in that lake. But, plot twist: it turns out that 100,000 kunimasu eggs had been transported to another lake 310 miles south of Tazawako, but the project was assumed to be unsuccessful.
It wasn’t until 2010 that a Japanese professor and his team discovered the salmon in the new location.
