All beaches in Sydney's east and south will re-open on Friday after there were no further sightings of a shark that fatally attacked a swimmer yesterday.
Authorities found human remains in the water at Sydney's Little Bay Beach after the attack, which happened just after 4:30pm yesterday.
Simon Nellist, 35, from Wolli Creek in Sydney's south, has been confirmed as the victim of yesterday's fatal shark attack.
Life savers said Mr Nellist sustained "catastrophic" injuries in the attack.
Mr Nellist was a certified diving instructor and his social media is filled with underwater pictures, showing him as an avid ocean lover.
NSW Police confirmed DNA from the victim's remains was used to help identify them.
Surf life savers continued to search for more remains today, and the shark, which is estimated to be between 4 to 5 metres long.
"Anything like this is a tragic circumstance and we just feel for the family and friends and we are trying to do the best we can to see if we can't locate the person," Shane Daw, General Manager Coastal Safety at Surf Life Saving Australia, said.
Little Bay Beach, about 20 kilometres south of Sydney's CBD, is a popular swimming spot near the entrance to Botany Bay.
Witnesses saw Mr Nellist's final moments in the surf near rocks at Buchan Point, at the northern end of the beach.
All beaches in Sydney's east and south, from Bondi to Cronulla, have been closed but will be re-opened tomorrow.
Drones were deployed this morning to support a helicopter in the search for the shark, and smart drum lines were set by the Department of Primary Industries to catch the animal.
"Whilst we have all assets on the water trying to locate the animal, we just want to make sure that there is no other danger to any swimmers in that area," Steven Pearce, from Surf Life Saving NSW, said.
Maroubra MP Michael Daley said Mr Nellist swam at the beach every day.
He described the attack as "horrific" and "heartbreaking", and thanked surf life savers who were among the first on the scene.
"They are supposed to be saving people's lives, not pulling body parts from the water," he said.
"But they are on duty. Always there to keep us safe and we are very grateful for that."
Wildlife scientist at Macquarie University, Vanessa Pirotta told the ABC that the size and behaviour of the shark, as reported by witnesses, pointed to it being a great white.
One man described to the ABC how he was fishing off rocks at Buchan Point and saw a man wearing a wetsuit swimming across the bay.
He said the man was right in front of him when he was dragged under the water by a large shark.
"He was yelling at first, and then when he went down, there were so many splashes," the man said.
Randwick Mayor Dylan Parker said the victim regularly swam across Little Bay and was "well known" to locals who frequented the quiet beach.
"The coast is our community's backyard," he said.
"Little Bay is normally such a calm, beautiful place, enjoyed by families.
"To lose someone to a shark like this is chilling. We are all in shock."
The shark attack has prompted the cancellation of the annual Murray Rose Malabar Magic Ocean Swim which was due to take place this Sunday.
Organisers of the community event, which raises funds for swimming lessons for disabled children, said their prayers and thoughts were with the victim's family.
"Out of respect for the swimmer and his family, and following wide consultation with Randwick Council and experienced, senior Surf Life Saving personnel, we believe that cancelling the 2022 swim is appropriate," they said in a statement.
They also thanked first responders and surf life savers.
The last fatal shark attack in Sydney was in 1963, at Sugarloaf Bay in Middle Harbour.
The most recent fatal attack off an ocean beach in Sydney was 1936.
In 1996, Patrick Bowring, the husband of celebrated magazine editor Nene King, went missing off Bondi on a diving expedition.
His wetsuit was later found with evidence of rips caused by a shark, but authorities couldn't say for certain if that had happened before or after death.
The body was never recovered.