Sydney's famous beaches, popular with surfers, looked more like a scene out of a horror movie today when the waters were stained blood red from an algae bloom.
Bondi Beach, as well as nearby Clovelly Beach and Gordon's Bay, were closed while authorities tested the water.
The beaches reopened in the late afternoon after the red algae, which was identified as Noctiluca scintillans or sea sparkle, begin to fade, the Sydney Morning Herald reported.
Algae blooms are most prevalent in hot, humid weather, the newspaper reported. Australia is currently enjoying the transition from spring to its summer, which begins in December.
While red algae isn't toxic, people were advised to avoid swimming in the algae-colored water because its high ammonia levels can cause skin irritation.
"It has got quite a fishy smell to it," lifeguard Bruce Hopkins told the Australian Associated Press. "It can irritate some people's skin but generally not much more than that."
Hopkins said the red algae was rare but definitely not unheard of.
Despite the warnings, it didn't stop some swimmers, including the one pictured above, from jumping in to the surf.
Earlier this month, Prince Charles visited Bondi Beach as part of a tour celebrating Queen Elizabeth II's Diamond Jubilee.