Children of shark victim call for return to the ocean at his memorial

More than a thousand people, many dressed in blue, gathered on Perth's Sorrento beach today to pay tribute to Greg O'Neill, who was killed by a shark just off the shore a few weeks ago.

Son Keelan O'Neill urged the crowd to return to the water and "keep doing the things that you love", adding that his father would have wanted everyone to "embrace life to the fullest".

The 63-year-old was swimming close to the shoreline in September when he was attacked and killed by a large great white.

He was the third person killed by a shark in Western Australia so far this year.

"He'd wish for you all to keep exercising … keep swimming, keep paddling, keep doing the things that you love as dad would have done, and the things that bring you happiness," Keelan O'Neill said.

Mr O'Neill's daughter Bianca thanked the crowd, saying: "The love, support and kindness we have received from this community is beyond belief."

"The water was dad's happy healing place, he wouldn't want anyone to feel unsafe, because of what happened."

The family was the first among the crowd to throw a handful of sand into the surf in memory of the beloved father, husband, brother and friend who frequented the beach.

Mr O'Neill's swimming group, the Sorrento Squids, were back in the water on Sunday, including, for the first time, the friend who was swimming with him on the day he was killed.

Shark safety this summer

Mr O'Neill's death was the third fatal shark attack in Western Australia this year and has reignited debate about how to keep beachgoers safe.

A 'catch-and-kill' order was issued for the great white shark in September, but it was called off when the shark was not located.

Head of the Sorrento Surf Life Saving Club, Robert Doherty, said a shark barrier at the beach in Perth's north would ease concerns.

"Would I be supportive? Yes," he said.

"I think something small, in an area of the beach, that doesn't affect the whole beach."

Many from the surf lifesaving club have been left shaken by the fatal attack, including members who witnessed the horror unfold firsthand.

"We gathered about 20-odd members that were directly involved that day and had a [counselling] session," Mr Doherty said.

"We thought it was really appropriate that the community does come together today to share a moment, dip your feet in the water."

Those who entered the surf on Sunday did so under the watchful eye of Water Police, Marine Rescue Surf Life Savers and two shark-spotting drones.