Tests show avian botulism caused the death of dozens of ducks at Fairmount Park in Riverside, city officials said this week.
Low levels of algae blooms were found in the lakes at the Riverside park at the beginning of the month.
A pump went down in mid-July that “caused the lowering of the lakes’ water level,” said Anthony Zamora, deputy director at the Riverside Parks Recreation Community Services Department in a video call on Tuesday, Aug. 13.
“Since then, it’s fully operational now. The water level is where it needs to be and we have water circulating the way it should,” Zamora said.
Botulism occurs from bacteria found in soil. In water, high temperatures, excessive plants and a low oxygen level can lead to its occurrence, according to the United States Geological Survey. When birds eat from the vegetation, they can become sick — affecting an animal’s nervous system and sometimes causing death.
Botulism outbreaks in birds is usually a low health risk to people, according to the United States Geological Survey.
Two duck necropsies were performed and avian botulism type C was found.
No dead ducks have been found in nearly three weeks, Zamora said.
The low water levels and high temperatures created the environment for avian botulism. The ducks may have been consuming the algae bloom or decaying plant matter.
A similar outbreak at the lake in 2011 was believed to have been caused by avian botulism.
“In the next couple weeks, everything should be back to where it was before this occurred,” said city spokesperson Phil Pitchford Tuesday.
RPW Services is supposed to treat the water with F30 and Tribune, two chemicals used to attack and rid the lake waters of algae.