The stocked habitat suddenly became uninhabitable.
State wildlife officials are trying to figure out why all the fish have died in a northern Nevada marina where the stocked fishery has flourished since the man-made lake was created nearly 15 years ago.
An estimated 100,000 trout, bass and catfish have died over the past month in the Sparks Marina along U.S. Interstate 80 east of Reno, apparently the result of a dramatic, unexplained drop in dissolved oxygen levels, Nevada Department of Wildlife spokesman Chris Healy said Wednesday.
Scientists say a bitter cold snap could have caused oxygen-poor waters to rise from the old rock quarry’s bottom to the surface, but they don’t understand what sparked the massive die-off.
The biologists confirmed low oxygen levels after a mid-December dieoff and a recent survey was worse than they expected. They state the fishery is essentionally destroyed.
They’ve been unable to detect any live fish in the 77-acre lake. Numerous dead fish have been removed from the lake’s shoreline, and Healy said it’s likely the rest sank to the bottom.
The count of 100,000 dead fish is probably low, they believe since the almost 1 million adult fish have been placed into the location since 1998. No chemical pollution is associated with the die-off. The stratification of the water likely led to the change that was ill suited to the fish living there.