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Wednesday, December 15, 2010

"Extinct" Salmon Species Back From the Dead

In the 1940's the black kokanee salmon was declared extinct.  Now, more than 70 years later this species of salmon, called "kunimasu" in its native Japan has been found alive and well in a lake more than 300 miles from where it was officially pronounced a memory.

Like all kokanee salmon, the black kokanee is a landlocked version of the sockeye salmon.  This salmon was originally found only in Lake Tazawa in northern Japan.  Lake Tazawa is Japan's largest lake with a depth of almost 1,400 feet.  A hydroelectric project built in 1940 and the resultant acidification of the lake led to the the species demise.

Professor Tetsuji Nakabo led a team of researchers from Kyoto University to Lake Saiko, Japan where they recently discovered a population of black kokanee that is large enough to sustain itself as long as the current lake conditions aren't degraded.  It's believed this population of salmon is descended from a stocking that took place sometime pre 1940 when 100,000 black kokanee eggs are believed to have been transported to Lake Saiko.

The black kokanee is an olive colored fish that grows to about a foot in length.  Researchers are hopeful that fishermen will leave the current population alone until the government develops regulations or protections.