HAZELTON, Idaho (KLIX) Thousands of fish have been found dead from the lack of oxygen at a lake near Hazelton.

According to the Idaho Department of Fish and Game, wildlife officers responded to calls from the public about numerous dead fish at Wilson Lake Reservoir. Idaho Fish and Game Regional Fishery Manager Doug Megargle said in a news release that nearly 30,000 fish are believe to have been killed by what is called a winterkill. Among the type of fish were bullhead, common carp, largescale suckers, yellow perch and Utah chub.

“Conditions must have been pretty poor since bullhead were among the dead fish at Wilson Lake,” said Doug Megargle – Regional Fishery Manager in the Magic Valley Region. “The unusually heavy snowpack this winter likely blocked all light penetration."

"It’s also possible hazardous materials washed in during the large spring runoff several weeks back; however, it’s very difficult to determine what that toxic material was when there were no reports of a spill or accident, and it’s been too long between when the fish died and when they were observed," Megargle said.

Officials say the winterkill is a result of heavy ice and snow pack blocking sun from reaching underwater vegetation that provide oxygen for the fish. Most winterkills go unnoticed because usually only a small number of fish are killed. According to Fish and Game, it is possible not many fish survived at Wilson Lake. The agency did not manage the lake and most of the fish came from flows out of the Snake River.