Researchers say a spike in number of shark attack fatalities could be related to human population increase
Researchers say a recent spike in shark attacks in Australia could be down to a population increase and therefore there are more of us, more frequently heading to the beach.
Earlier this week a 41-year-old surfer died off Ballina in New South Wales. It was the fifth shark attack fatality in Australia in 12 months, with three of those in NSW.
Dr Daniel Bucher, senior lecturer in marine biology and fisheries at Southern Cross University, said trends indicated an overall decline in shark numbers.
“In 1990, there was 17 million of us, now there’s about 23 million,” he said.
“So there are more of us, in general, and a greater proportion are actually going in the water.”
The warmer water along the northern coast of NSW has also been blamed for the recent shark activity in the area.
However, Mr Bucher said it was hard to predict if a warm water pattern would continue due to constant changes in winds, rainfall and ocean currents.
“Because it’s so variable, and there are so many local factors at play it would be hard to tease out what the long-term trend is for the east coast (to be) warmer,” he said.
“It might mean that we see tropical species more often.
“Tiger sharks for instance, they're the ones we see more often this time of year, whereas the great whites tend to come up during the winter.”
Mr Bucher has also warned that people had to be cautious about assumptions on shark numbers without data.
“A couple of years ago there was a headline that helicopters off Sydney had seen more sharks this year than last year,” he said.
“Somewhere down the bottom (of the news story) they quoted their flying hours, they'd flown for that many more hours the second year.
“If you divided the number of sharks by the number of flying hours they'd actually seen less sharks per hour of flying time.”
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