Red algae closes beaches in Sydney - in pictures

While the red algae, known as Noctiluca scintillans, or sea sparkle, has no toxic effects, people are still advised to avoid swimming in areas with discoloured water because the algae, which can be high in ammonia, can cause skin irritation Photograph: William West/AFP/Getty Images

The red algae closed some beaches for swimming, including Bondi Beach Photograph: Newspix/Rex Features

A mother and her daughter look at the water at Clovelly Beach Photograph: Newspix/Rex Features

A seagull stands amid the red algae bloom Photograph: Newspix/Rex Features

A man swims in a pool next to the closed beach Photograph: Newspix/Rex Features

A boy walks past red algae bloom discolouring the water at Sydney's Clovelly Beach Photograph: William West/AFP/Getty Images

A girl looks at the algae bloom at Clovelly Beach, commonly known as sea sparkle, as it drifts in on the tide Photograph: The Sydney Morning Herald/Fairfax Media via Getty Images