TEMPE, Ariz. -- A bacterial or viral disease is killing off fish by the thousands in Tempe Town Lake.
The disease is isolated to the lake's carp population and city officials said the lake is safe for humans to be near.
"These [diseases] are isolated to fish, in this case they're isolated only to the carp species," said Rick Amalfi, vice president of Aquatic Consulting, a Phoenix environmental services company.
Recent tests done by the company found no inherent dangers to humans near the lake.
"The water quality is fine. We have plenty of oxygen in the lake," Amalfi said. "We always check for golden algae because that's been responsible for a lot of fish kills because of the toxin it produces and we don't find any of that in there."
But some lake visitors are unhappy with the sight and smell of rotting carp carcasses around the lake.
"For the average person going by the lake it is pretty stinky," Amalfi said. "When you really get the odors is when you get a windy day and a large number go down in a corner and you happen to walk by that corner, it's going to be smelly. There's no getting around it."
The carp started to die off two weeks ago when the lake temperature rose. The bacteria thrives at certain degrees, which is the current temperatures.
"There are various bacterial and viral diseases that the fish get and the carp are susceptible to them when the water temperature is where it's at right now," said Amanda Nelson, a spokeswoman for the city of Tempe.
Nelson expected the fish to stop dying in a few weeks when water temperatures warm up further and Amalfi agreed.
"Our best guess is when the water starts warming up a little bit the disease usually dies out," Amalfi said.
Until then, Nelson said the dead carp may be a small nuisance but, they will not affect any events taking place near the lake. She said crews are working to remove the carcasses.
Amalfi said Aquatic Consulting has increased its normal cleanup efforts. Crews will be on and around the lake daily until the disease dies out.