SPARKS, Nev. (AP) - Another round of tests confirmed there's no toxins in the Sparks Marina and its oxygen supply is slowing rising after a sudden drop in oxygen levels choked off the man-made lake's entire fishery.
The massive fish die-off in December claimed an estimated 100,000 trout, catfish and bass at the former gravel pit along U.S. Interstate 80 just east of Reno.
Nevada Department of Wildlife biologist Chris Crookshanks tells the Reno Gazette-Journal new tests found nothing unusual beyond the lack of dissolved oxygen.
Scientists believe a week of unusually cold weather caused a sudden turnover of the 77-acre marina, sending the warmer, oxygen-rich waters from the surface to the lake's bottom.
They're optimistic the oxygen content is recovering and more fish can be restocked there in the coming months.