Heat is suffocating fish in Lake Travis

TRAVIS COUNTY, Texas (KXAN) - Dead fish have been washing up on the banks of Lake Travis near Mansfield Dam .

According to the Lower Colorado River Authority , suffocation is to blame.

"We were kind of curious what was going on," said Chad Sitzmann who lives close by and was out taking a swim a friend and their dogs. "I was more concerned about the dogs actually."

LCRA water quality supervisor Bryan Cook said only fish are the ones suffering. Dead striper bass and freshwater drum are scattered along the shore.

Right now, the water temperature near the surface is in the 90s, but 180 feet down at the bottom it is a cool 54 degrees. That is where the fish like to be, but the deeper they go the less oxygen there is to survive. The change in water temperature creates stratification , which means layers in the lake form and keep oxygen from flowing to the bottom.

Water testing is ongoing. While an increase of algea can also deplete oxygen levels, Cook said test results have shown that is not the cause.

So far, dead fish are only floating up near Mansfield Dam. LCRA said that is because it is the deepest point in the Highland Lakes. If the heat continues, they predict pretty soon no oxygen will be left at the very bottom.

Buzzards have been in heaven, but water quality experts say only a small fraction of fish have been affected. The last heat-related fish kill struck in 2007.

Only cool weather will allow oxygen to flow back to the bottom. Typically, that happens in October.

"If that's part of the natural cycle, then that's the way it's supposed to be," said Sitzmann.

For more information from LCRA click here .