Nevada state wildlife officials are completely baffled as to the reason all the fish in a northern Nevada marina have died.

Over 100,000 trout, bass and catfish have been found dead in the past month in the Sparks Marina near Interstate 80 east of Reno.  A sudden dramatic drop of dissolved oxygen levels in the water is being blamed for the deaths.

Officials say they have no reason for the decreased oxygen.

Nevada Department of Wildlife spokesman Chris Healy said that the 100,000 figure is likely a conservative estimate for the fish kill. The Department had been stocking the lake with about 1 million fish since 1998.

“We don’t know if any small fish have survived, but for all intents and purposes, the fishery doesn’t exist anymore,” Healy told the Associated Press.

The Department stocking of the lake scheduled for late February has been cancelled pending further testing.