Readers ask: What’s that in the water at Berkeley’s Aquatic Park?

Algae at Aquatic Park. Photo: Yarbutus

Berkeleyside had several inquiries in the past week about some new plant life in the water at West Berkeley’s Aquatic Park.

It’s a particular concern given the announcement in late June that Lake Temescal has been closed due to toxic algae. Last fall, Berkeley’s Lake Anza was closed for the same reason. And it’s not the first time.

Asked ‎Carolyn Weil‎ on Facebook on Monday: “Does anyone know what the stuff floating on Aquatic Park is and why? seems like this … bloom spread almost overnight!”

Berkeley city spokesman Matthai Chakko said several things are happening: yellow algae, along with “grass that’s growing up from the bottom of the lagoon,” as well as dead grass. Berkeleyside shared a photograph from a community member that showed the vegetation in vivid colors.


Chakko told Berkeleyside staff had gone to Aquatic Park to take a close look at the plant matter: “They didn’t see discoloration. It was yellow, which is typical. The reds and the blues of the photo weren’t there.”

“Morning run past night heron looking for breakfast.” Photo: Karuna Jaggar

He said there was no indication that the algae is toxic.

“There is yellow algae, but it is on top of the dead grass,” he said.

Chakko said a contractor will be cleaning up the vegetation next week as part of regularly scheduled maintenance the city does every July.

The algal bloom was spotted in Aquatic Park on June 24. Photo: Emilie Raguso