Sharks have been around for hundreds of millions of years – long before humans – so it’s no surprise that stories about ‘close encounters’ often draw an eye-roll. But our local beaches have been far from business as usual these past six months.
The first shock came on 6 September 2025, when experienced surfer Mercury (Merc) Psillakis, 57, was fatally attacked by a great white shark halfway between Long Reef Beach and Dee Why, only the second such fatality since 1963.
Then there was the unprecedented cluster this summer. On 19 January 2026, Andre de Ruyter, a 27-year-old musician, paddled out at North Steyne and was bitten by a bull shark. He was in cardiac arrest by the time he was dragged onto the sand by fellow local surfers Ash Bowler and Eduardo Botti.
We were there that day on Manly Beach as the musician was resuscitated. It had seemed improbable he would survive. And yet, through the incredible efforts of his rescuers, first-aiders training at North Steyne, a trauma consultant who happened to be on the beach, off-duty doctors and nurses who sprinted down, and a rescue helicopter that landed to administer blood on-site, Andre survived.
His family confirmed with the Manly Observer in February that his feeding tube had been removed and he was ‘officially a survivor’. He has had a leg amputated below the knee, but he is alive.
Tragically, 12-year-old Nico Antic was not so fortunate. He was fatally bitten one day before at Vaucluse’s Jump Rock.
Then the near misses.
Just hours before the attack at North Steyne, an 11-year-old local boy was knocked off his board by a bull shark and had a chunk clean bitten out of it at Dee Why Point. Barely half an hour before the Manly attack, a rider at Freshwater told us he was knocked clean off by a bull shark.
So has there been a real and considerable change in the sharkiness of our Northern Beaches shoreline, and with it a genuine increase in danger?
For Mike Psillakis, Merc’s surviving twin, it is undeniably so. The contention, he says, is agreeing on what should be done about it.
Mike still surfs every day; it’s essential to his wellbeing. But he does not consider the waters safe and expects next summer to be “even worse.”
“It is undeniable. I think 99 per cent of surfers would agree that there are more sharks, and their behaviour has changed.”
“It is undeniable. I think 99 per cent of surfers would agree that there are more sharks, and their behaviour has changed,” he said.
That warmer waters are keeping sharks around longer is now established science. But warmer by just 0.6 degrees, lingering for an average of one extra day a year, it’s not nearly enough to explain our recent experiences.
The Heavy Rain: A Perfect Storm
The weekend before the cluster of attacks, Sydney recorded its heaviest rainfall in decades. The falls on the northern end of the beaches broke records.
This produced precisely the conditions bull sharks thrive in. Record rainfall flushed nutrient-rich runoff from farms and wastewater treatment plants into the river system and harbour. This attracted baitfish; the baitfish attracted larger predators; the murky, brackish water then reduced shark visibility, causing them to rely instead on hearing, electroreception, and their mouths to investigate. For humans, that can mean a catastrophic bite.
Chris Pepin-Neff at the University of Sydney has made a similar argument for years, noting that cleaning up Sydney’s stormwater pipes is, in itself, a form of shark bite prevention.
Surf Life Saving NSW CEO Steve Pearce called the January cluster “unprecedented” and told the public plainly: “If you’re thinking about going for a swim, just go to a local pool.”
The expectation now is that the sharks will eventually move on as the water cools and the drama will become yesterday’s news.
A new school of thought
In January Shokoofeh Shamsi, a professor of veterinary parasitology at Charles Sturt University, published a piece in The Conversation arguing that the conventional focus on rainfall and murky water tells only part of the story. The author contends that pollutants, pesticides and parasites flushed from land into coastal waters may be shaping not just where sharks and humans cross paths, but shark behaviour itself. They are exploring a link between pesticides, parasites and animal risk-taking and aggression.
But for Mike, who remembers swimming in a sea of “poo and tampons” whenever it rained near the sewerage outlet at North Head back in the day, polluted, pesticide riddled nutrient-rich water is hardly a new thing on our beaches.
He contends the anecdotal evidence from surfers and fishermen is pointing to a clear population explosion that needs to be managed through targeted species culling, to restore the balance.
The local surfboard shaper told us: “We do not have comprehensive bull shark population data in Australia. Yet we confidently claim they are not overabundant. That is not science. That is ideology disguised as science.”
So we went to the Department of Primary Industries (DPI) and asked for the facts. What data do they have on our local bull shark population?
It turns out there isn’t any.
“There are no formal population estimates for bull sharks so there is no verified or scientific evidence of increasing bull shark numbers.”
“There are no formal population estimates for bull sharks so there is no verified or scientific evidence of increasing bull shark numbers. Since the deployment of SMART drumlines in 2015, catch rates of bull sharks on SMART drumlines and in nets is consistent,” a spokesperson explained.
Dr Vanessa Pirotta, a marine scientist with the Marine Predator Research Group at Macquarie University says not having the answers to how many bull sharks there are is okay. “The reality is we can’t ask every shark to stop swimming so we can count them,” she says. “But we do need updated science to inform an updated understanding of bull sharks in our waters. That means government can then directly inform the community.”
DPI says it is on the case. The NSW Government has recently announced millions not just in drone surveillance and shark listening stations but also in focused research on bull sharks in Sydney Harbour. But (DPI) has made it clear a cull is not on the cards.
Rather than there being any significant change in population, DPI lays the blame for the unprecedented attacks on the unprecedented rains, effectively flushing bull sharks out of the rivers and harbour and onto the beaches.
This was why the increased presence of sharks was no surprise to Dr Pirotta, too.
“We need to use the existing science to help create better communication around ocean swimming and safety; like how we have a UV index for the sun, let’s have ideal shark conditions scale.”
So, what does the science say?
Generally, the science tells us the individual risk of a shark bite remains very low. The same science tells us that warming waters, extended bull shark residency seasons, and extreme rainfall events are making encounters more likely over time. Those trends are not going away.
If the net result of new research is a recommendation to stay out of the water, few will be pleased, and fewer still will obey.
Bull sharks overstay summer vacay as waters warm, says researcher
