In the well orchestrated war against shark nets in NSW, truth has long been the first casualty. The fatal shark attack on a 57-year-old man at Dee Why Beach in Sydney on 6 September is arguably the second.

The foot soldiers in this war have the worthy goal of saving the lives of marine animals caught in the nets. I share that goal and look forward to the day when netting can safely cease. But until it arrives, as a physician, I place the protection of human life above all and, as a clinician scientist, I ask that governments, state and local, implement policy on the basis of evidence.

I also plead for the responsible media to restore balance in a debate that carries deadly consequences. Fact check claims, cite the published evidence and interview people on both sides of the debate.

The first casualty

Two days after the fatal attack on 6 September, the Sydney Morning Herald published an opinion piece by a member of the Humane World for Animals Australia titled “Shark nets don’t protect people and they never will”.

In truth, the evidence that shark nets protect human life is irrefutable. There were nine young men, at a median age of 17, mauled to death by sharks on Sydney’s ocean beaches in the decade before the nets were installed in 1937. Until the tragedy at Dee Why, there had been none at a netted Sydney beach in the 88 years since, despite massive increases in population and ocean use, including at high-risk times of dusk and dawn. The probability of this occurring by chance is less than one in a billion. Little Bay beach, where the fatality occurred in 2022, was not netted.

Replication of findings is key to science and therefore to evidence-based policy. The NSW evidence for effectiveness was replicated in Durban, South Africa, where seven fatal shark attacks occurred between 1943 and 1951; after net installation in 1952 there have been none whilst frequent fatal attacks have continued in other provinces with unnetted beaches. Nets were installed in Queensland in 1962. There had been 36 attacks, with 19 fatalities, at ocean beaches from 1916 to 1962 ; there have been two in the 63 years of netting.

Don’t ‘give the randomness of mathematics the mystique of causation’

These are inconvenient truths. One bizarre attempt to refute them, by an environmentalist, was re-quoted in an opinion piece in the SMH on 13 September: to accept the overwhelming evidence of efficacy was to “give the randomness of mathematics the mystique of causation”. Mathematics is the least random science and the foundation stone for all others. No new effective medical treatment would get to market if high statistical probabilities of benefit could be dismissed as the “randomness of mathematics”. To Albert Einstein, mathematics was “… the poetry of logical ideas”.

More concerning is that this tendentious nonsense was “retweeted” by a good journalist in a reputable newspaper in a piece aimed at putting pressure on the NSW Government to remove nets.

‘Nets can’t possibly work because sharks can swim above, below and around them’

It is an argument that has superficial appeal, but it has just one problem: the empiric, replicated data are irrefutable.

Why the netting program has been so effective is unknown. One theory is that it has resulted in sharks moving their colonies away from netted areas; this is supported by data on shark numbers, collected since 1950, showing a reduction in numbers off Sydney beaches.

As a physician, if I had a drug for a fatal disease that succeeded with the statistical probability of shark nets in a real world trial, I would not be worried by incomplete knowledge of how it works.

‘Everyone knows removing the nets will make the beaches safer’

Recently the campaign has stepped up a gear. Not only are the nets ineffective, they make the risk to humans greater, the claim being that bycatch attracts sharks, bringing them closer to shore, increasing the risk of human contact.

This aims to give governments and councils comfort in removing the nets.

Again, the evidence refutes this. The nets have trapped bycatch since 1937 but there have been no fatal attacks at a Sydney netted beach until now. The bycatch may have attracted sharks, but they have not gone on to attack humans. At the time of the 2022 fatality, Little Bay beach was not netted.

The ABC TV 7pm news, a trusted source, in its coverage of the fatal attack at Dee Why, included a clip of an environmentalist saying “everyone knows removing the nets will make the beaches safer”. A balancing interview, citing the known facts, was not included.

‘Shark nets are old technology, the new technologies are much better’

Again, the evidence rejects this. Port Macquarie beaches are unnetted, but have drones with high-resolution cameras, AI-powered image recognition with live feeds to trained operators, shark listening stations and SMART drumlines. The full suite of new technologies did not prevent a near fatal attack (right leg removed) in July 2024, nor a less severe attack (right foot removed) in August 2023. The new technologies are valuable adjuncts but not yet a replacement for nets. Hopefully, such technology will emerge soon.

Fortunately, the new technologies are maximising the rapid release of bycatch alive. Further, nets are fitted with acoustic warning devices, with net lights in trial to deter turtles and net surveillance by contractors and drones increased. Over the last three years, the number of non-target animals/year killed by enmeshment has dropped to 140/year, fewer than three/beach/year across the 51 netted beaches.

Why is the Queensland Government putting in more shark nets, calling them a “proven safety measure”?

The Queensland Government, informed by a KMPG review, announced in May an expanded “Shark control program”, noting :

“The new plan combines proven safety measures like shark nets and drumlines at more Queensland beaches whilst prioritising innovative technologies like drone surveillance and whale-deterrent measures”.

“We’re striking the right balance between ensuring swimmer safety and maintaining a healthy marine environment …”

Since both governments have access to the same world data, the contrast to NSW can only be understood as a contest of values, not evidence: what does one value more, reducing the risk to human life or preventing the loss of marine animals in the process?

Possibly, the second casualty

The tragic fatality at Dee Why, the first at a netted Sydney ocean beach in 88 years, followed the removal of the nets a month earlier, at the end of March. This was the only thing that changed in 2025. Of course, it cannot be established that this resulted in the fatal attack but equally, and importantly for the NSW Government, it can’t be excluded.

Since 1989, the nets have been removed for four months, from 30 April to 1 September, due to the whale migration; this year they were removed for five months, reportedly due to a turtle migration in April. The early net removal was proposed as a trial, presumably to provide data on two questions. Did it protect turtles? Did it endanger human life? Seven turtles were killed in nets in the trial season, three fewer than the 10-year average of 10 and one man lost his life.

Three beachside Councils put pressure on the NSW Government for this trial and a proposed removal of the nets for an entire season at three selected beaches in 2025/2026. The latter was abandoned after the Dee Why tragedy and the message of a “clear and present danger” it delivered.

It isn’t just about life and limb

Author and daily ocean swimmer, Julia Baird, attributes the joy of ocean swimming to “the connection with nature it provides, fostering a sense of awe and wonder that offers strength, calm, and perspective during challenging times”.

Millions of people enjoy Sydney’s ocean beaches every year, including many who regularly swim or surf, some daily. It is a lifestyle gift we are so lucky to have and to share with visitors. For many, interference with the shark protection program would increase anxiety and reduce the pleasure of a joyful activity that contributes enormously to both physical and mental health.

Conclusion … in the war of the nets it is time to put people in front.

In announcing the Queensland’s expanded shark net program in May, the minister didn’t hold back on criticism of predecessors:

“It’s clear the program had lost its way …. and put people after the demands of environmental activists.”

In this context, the NSW Government has shown restraint, moving in tiny steps despite intense pressure. Tiny steps which the tragedy at Dee Why should cause a halt and retreat.

I have long admired much of the achievements of environmental activists, but not when it puts human life at risk.

In the war of the nets, it is time for all governments to put the protection of people first.

The views expressed in this article may or may not reflect those of Pearls and Irritations.