Terrified fishermen have filmed the moment a five-metre-long great white shark menaced their small boat just off the coast of Rottnest Island shortly after the fatal attack on a devoted dad-of-two.

Steven Mattaboni, 38, died on Saturday morning after being mauled by a great white shark about 1km off the popular WA tourist hotspot.

He leaves behind a wife and two young daughters, one of whom was born just four months ago.

Mattaboni had been spearfishing with a group of friends at Horseshoe Reef when he was attacked.

Emergency services frantically worked to try and save his life but he died shortly after.

A number of sighting of great white sharks were reported on the WA government’s SharkSmart website around the same time of the attack.

On Sunday morning, fishermen in a spot close to where Steven was attacked filmed the moment a shark circled their small boat.

“That’s a big shark, man,” one boatie said.

Fisheries officers spent Sunday searching the area for the shark.

Steven’s wife earlier paid tribute to her husband, describing him as a devoted father who was fiercely loyal and endlessly generous.

“Our hearts are irrevocably broken by the loss of Steven,” she said.

“Steven was a devoted father to our two beautiful daughters. An avid fisherman and spearfisherman, who lived and breathed the ocean.”

“The world has lost a truly one-of-a-kind gentleman, and our daughters have lost an incredible father far too soon.”

Steven’s mates pulled him from the water after he was bitten on both lower legs and rushed him back to shore, where paramedics worked frantically for about 30 minutes on the jetty in an attempt to save his life.

WA Police Sergeant Michael Wear described the incident as “quite horrific scenes for all involved”.

“His friends have actually witnessed the horrific event,” Wear said.

“The victim was on the surface at the time, about 20 metres away from the vessel.”

Authorities believe the attack involved a four-metre great white shark, while Surf Life Saving WA reported a five-metre white shark had been spotted about 80m offshore again on Sunday morning.

A search operation is set to resume on Sunday, with emergency services continuing to monitor the area.

Despite the renewed shark sighting and ongoing search activity, beaches on Rottnest Island have remained open, with authorities urging beachgoers and boaters to exercise caution and monitor shark warnings.

The grieving family thanked emergency services and first responders who “worked so tirelessly” to try to save him, while asking for privacy as they navigate the “incomprehensible loss”.

The death adds to a string of shark attacks reported around Australia this year.

In January, 12-year-old junior lifesaver Nico Antic died after a suspected bull shark attack at Shark Beach in Sydney’s east, while 27-year-old Andre de Ruyter lost a leg in an attack on Sydney’s Northern Beaches just days later.

Renewed calls for AI shark detection technology

The tragedy has renewed calls for advanced shark detection technology, with marine life ranger David “Sharky” Baxter telling Sunrise on Sunday the Rottnest attack was a “textbook perfect attack” by a large predator.

“He was spearfishing. That attracts predators around there, wrong place at the wrong time,” Baxter said.

Baxter, who was among the first responders to the fatal shark attack at Manly earlier this year, said autonomous AI-powered drones could help prevent future attacks at high-risk beaches.

“The system is fully AI-oriented,” he explained.

“If it spots something in the water that it’s been trained to identify as a potential target, it hovers above that target, activates its onboard alarm, and will stay above that, tracking that shape in the water.”

He said the technology could be deployed at popular beaches during peak periods, with each base unit estimated to cost between $20,000 and $25,000.

Australia recorded the world’s highest number of fatal shark attacks last year, according to the International Shark Attack File released in February.