It’s “extraordinary”, says shark researcher Chris Pepin-Neff: four shark bites within 48 hours, and three of them within a 15km (9-mile) stretch of Australia’s east coast.
On 18 January, a 12-year-old boy was taken to hospital with critical injuries and later died after being attacked while swimming in Sydney Harbour. The next day, an 11-year-old’s surfboard was bitten at Dee Why beach, hours before a man was attacked at nearby Manly and taken to hospital in critical condition.
Then, on 20 January, a fourth surfer “sustained a wound to his chest” after a shark bit his board some 300km up the coast.
“This is the closest – in both proximity and in time – series of shark bites that I’ve ever seen in my 20 years of research,” says Pepin-Neff, who is an associate professor of public policy at the University of Sydney.
The succession of incidents caused alarm and dozens of beaches have been closed because of fears of more attacks. Calls for shark culls have gathered momentum.
Experts, however, have cautioned against such measures, advocating instead for a greater awareness of shark behaviour and urging a rethink of humans’ relationship to these fish.
Many factors may have contributed to the recent series of incidents, they say – and the sharks are not the problem.
Why suddenly so many shark attacks in Australia?
Non-provoked shark attacks are usually precipitated by environmental conditions, attractants in the water, or both.
The three recent incidents in Sydney – all of which are thought to have involved bull sharks – followed several days’ worth of heavy rain, during which the city’s official weather station recorded 127mm of downpour within 24 hours – its wettest January day in 38 years.
That rainfall would have created “perfect conditions” for bull sharks, according to Rebecca Olive, senior research fellow at RMIT University.
“Bull sharks thrive in warm, brackish water, which most other sharks flee,” she told the BBC. “They love river mouths and estuaries, so the freshwater that flooded off the land following the recent rain events was perfect for them.”
Olive and other experts further note that this freshwater would have likely flushed sewage and nutrients into the sea, thus drawing in bait fish and, in turn, sharks.
“There’s clearly an attractant in the water,” Pepin-Neff says, suggesting that a “perfect storm” of low salinity freshwater could have created a “biodiversity explosion”.
“The bait fish come to the surface, the bull sharks come to the surface, everybody’s in the near shore area – and now we have a problem.”
Are shark attacks increasing overall?
Official statistics show that shark bite incidents in Australia have gradually increased over the past 30 years – rising from around eight to 10 per year in the 1990s, to yearly averages in the mid-20s from the 2010s onwards.
That doesn’t mean sharks are becoming more aggressive, though. More likely is that the higher numbers reflect better data collection, as well as a number of compounding human factors.
These include a growing coastal population, an increased uptake of water sports and thicker wetsuits that allow swimmers to stay in the ocean for longer.
“The number of total encounters is definitely much higher than it was, just because the population of people who go in the water and do all these things is really high,” Pepin-Neff explains.
They also point out, however, that the rate of shark bites “doesn’t tick up at the amount it should for the proportion of people who are going in the water and doing more things”.
Olive echoes this point, noting that “given how many people use the ocean each day, incidents and attacks are relatively uncommon, and fatalities are even less common”.
If it seems as though sharks are becoming more prolific or dangerous, Olive suggests this may just be a result of them being more visible to members of the community – whether because of better reporting systems, the proliferation of drone footage or the outsized attention that shark encounters receive from the media.
Pepin-Neff adds that broad, imprecise language around encounters is likely fuelling fears and distorting people’s understanding of the risk.
When shark sightings, encounters and bites all get conflated under the catchall umbrella of an “attack”, the danger seems greater than it is.
“There is a problem in being able to meaningfully describe what happened without using the words ‘shark attack’,” they explain. “And that creates a more emotional community experience that is slightly different to what actually happened.”
Do shark culls work?
In the wake of Sydney’s recent flurry of shark attacks, heightened fears have reinvigorated calls for a cull. Typically, this would involve using nets or baited drumlines to catch and kill sharks near popular beaches.
Experts reject the suggestion.
“I can understand when there are calls for culls in response [to an attack]… but I’m strongly opposed to culling sharks in order that we can maintain an illusion of safety while surfing or swimming in the ocean,” says Olive.
Pepin-Neff, meanwhile, stresses that scientific research does not support shark culls as an effective method of reducing the danger of an attack.
“It just doesn’t work,” they say. “It makes politicians feel better, and it makes activists feel better, and it makes nobody in the water any safer.”
In cases of shark encounters, they add, the variable is not the sharks themselves, but rather the attractant that’s drawing them to the area.
“It doesn’t matter if you kill all the sharks in Sydney Harbor – if there’s a shark up the coast and the attractant is still in the water, then the shark’s going to come in.”
How can people avoid shark attacks?
Both Olive and Pepin-Neff suggest that the best way to minimise risk is to be more conscious and wary of the factors that exacerbate the likelihood of a shark encounter. On an individual level, this might mean avoiding swimming and surfing after heavy rain. For councils it might mean creating more shark enclosures where people can swim safely.
More broadly, however, they emphasise the need for beach-goers to adopt a less idyllic and more pragmatic attitude towards the ocean.
“In Australia we’ve got to treat the beach like the bush,” says Pepin-Neff. “Australians know how to navigate the wild. We just need to reinforce that the ocean is still the wild.”
