The Valley's record-breaking heat wave is taking a toll, even underwater. Thousands of fish turned up dead last week in a popular Scottsdale fishing pond.

Arizona Game and Fish stocks the pond at Scottsdale’s Eldorado Park with trout, catfish, bass and sunfish for recreational fishing.

But Scott Gurtin, community fishing program manager with Arizona Game and Fish, said hot weather recently raised the water temperature in the pond to 90 degrees.

“When the water warms to that level, the pond can’t hold as much oxygen as it can when, let’s say, the water is in the mid-60s,” Gurtin said.

Gurtin said recent monsoon activity also increased sediment in the water, which further depleted oxygen. 

“The oxygen level at Eldorado pond had dropped to literally zero. There was no measurable oxygen in the water at that particular site,” Gurtin said.

He said the pond does have air diffusers to keep oxygen flowing, but in these extreme conditions, they weren’t enough.

Gurtin said these die-offs aren’t common but do happen occasionally in extreme summer weather.