27/11/2012 06:06 GMT | Updated 28/11/2012 06:22 GMT

Bondi Beach Closed By Red 'Sea Sparkle' Algae (PICTURES)

Surf's up! But wait, what's that red stuff?

No, it's not ketchup and Jaws hasn't attacked - it's just algae.

The marine plant managed to close Australia's world-famous Bondi Beach, as well as Sydney's Clovelly Beach.

bondi beach turns red

A swimmer stops short of a red algae bloom at Sydney's Clovelly Beach

If you want to cool off, the algae, known as Noctiluca scintillans or sea sparkle isn't toxic - but it can irritate the skin.

Local lifeguard Bruce Hopkins said it made the water look like "tomato sauce."

australia algae

The red algae, known as Noctiluca scintillans or sea sparkle, has no toxic effects

Irene Eristian, 33, told the water colour was "intense." "I wasn't sure if I should let my daughter into the water as I wasn't sure what it was."

Bondi Beach Turns Red

This isn't the first time water has turned blood-red this year. In August a lake in the South of France made the headlines after changing colour, but experts said the phenomenon was "completely natural".

Patricia Estebe from Camargue's tourist office explained: "This phenomenon is a result of the salt content in brine shrimp Artemia salina and algae Dunaliella salina. When the salt concentration is very high - which is the case before harvest - the brine shrimp die and saline algae proliferates giving this unusual colour. "