Woman suffers serious injuries after shark attack in Sydney Harbour

A 29-year-old woman is recovering in hospital after a suspected shark attack in Sydney Harbour left her with serious injuries to her leg.   

The woman was swimming at a private wharf at Billyard Avenue, Elizabeth Bay on Monday evening, approximately two kilometres from the Sydney Opera House.   

It's understood she had only just jumped from the wharf to swim to a nearby boat when she was attacked and bitten on her right leg by a suspected bull shark.    

Multiple witnesses jumped in and pulled her back to land and emergency services quickly dispatched a helicopter carrying blood transfusion products to the scene.    

One of the witnesses was a veterinarian who applied a tourniquet to stop the bleeding.    

"My wife's a vet and she basically bandaged it up," the woman's wife told 7NEWS.   

"The bone's broken, it's pretty hectic but she seems to be ok."   

She expected that, if the victim had been further out in the water, she would not have survived.   

NSW Ambulance said the woman suffered critical injuries alongside severe blood loss from injuries to her lower leg.   

While the helicopter was standing by, the woman was taken to St Vincent's Hospital by road and remains in a serious condition.    

She is expected to undergo surgery later on Tuesday.    

Another shark attack victim, Paul de Gelder, who was a military diver and now advocates for sharks and shark safety, said "our beautiful harbour can also be a dangerous place and we must take responsibility ourselves when entering these dangerous places.   

He added, "my best wishes go out to the young lady that was bitten yesterday.   

"If I can be of any help or support then I welcome her to reach out."   

A local told 7NEWS "it's pretty scary but it's nothing that has happened in a long time".