A Sydney woman is “lucky” to have survived the first confirmed shark attack in Botany Bay in 25 years, Randwick Mayor Lindsay Shurey says.

The 55-year-old swimmer is recovering at St George Hospital after she was bitten by a suspected great white shark at Little Congwong Beach on Friday evening.

Randwick City Council says she was assisted about 20 metres to shore where paramedics treated “serious wounds” on her leg, but she is now in a stable condition.

Ms Shurey said the woman underwent surgery on Saturday morning for a “very large bite” below her right knee.

“I think she’s very lucky to still have her leg… and to survive,” Ms Shurey said.

“She was swimming at dusk, which is never really recommended.”

Ms Shurey said locals are reeling at the news of the first confirmed shark attack in the area in 25 years.

“We’re all a little shocked and concerned,” she said.

“I’ve lived in this area for 35 years and we have no knowledge of anything like this before.”

#Lifesaver21 working with @sls_sydney, @RandwickCouncil, @nswpolice and National Parks after a shark attack yesterday at Congwong, La Perouse. Aerial patrol of beaches conducted this morning. Beaches remain closed. pic.twitter.com/JAfyPhfFa9

— Westpac Life Saver Rescue Helicopters (@Lifesaverhelo) February 23, 2018

Lifeguards have since closed the La Perouse beach, along with the surrounding Congwong, Frenchmans and Yarra beaches, for at least 24 hours.

“Council Lifeguards will be stationed at the usually unpatrolled beaches on Saturday to advise swimmers not to swim,” Ms Shurey said.

There are no shark nets currently at those swimming spots, which usually only get the occasional smaller shark including grey nurses and wobbegongs, she said.

But Randwick Council will take advice on whether to install any nets following the incident.

A Department of Primary Industries shark biologist has examined photographs of the woman’s “severe injuries”.

“A White Shark is most likely responsible for the incident,” a DPI spokesperson said.

-AAP