Canberra [Australia], September 7 (ANI): A childhood friend described the 'heroic' final act of a surfer who steered his friends to safety before being mauled by a shark at Sydney's Northern Beaches, as authorities race to find the shark, ABC News reported.

A frantic effort has been underway to find and identify the species and size of the shark after it claimed the life of Mercury Psillakis in a morning surf at Long Reef Beach.

Psillakis, a 57-year-old who is survived by a daughter and wife, suffered catastrophic injuries in the attack on Saturday.

He routinely walked the couple of hundred metres from his home to the beach to go surfing, former professional surfer and friend Toby Martin said.

'A really deep loss for us on the eve of Father's Day for an avid surfer, loving father, loving husband, great son and great person. [He] was just doing what he wanted to do, in a place where he loved doing it,' Martin said, as per ABC News.

The 51-year-old Dee Why local has talked to the surfers who were out with Psillakis on the day and a lifeguard who helped render treatment.

The fatal attack and ongoing search for the shark have roused mixed feelings in regular beachgoers.

Jemma Cook, a regular at Dee Why beach, said the tragedy had hit 'so close to home' and sent 'shock waves through the whole community'. 'You all know the dangers when you go out surfing and swimming; you always hear the stories--and think it's somewhere else,' she said.

Long Reef and Dee Why beaches remain closed by the local council until further notice.

Surf Life Saving New South Wales is surveilling the waters using drones and a helicopter.

Meanwhile, the state government is doubling down on trying to divert sharks away from beaches by increasing the number of smart drumlines in the area from three to five until Monday evening, as per ABC News. (ANI)