Great white sharks are said to be attracted by the cooler waters
© Getty ImagesGreat white sharks are said to be attracted by the cooler waters
Andrew Sharpe was killed in an attack while surfing on Friday at Kelp Beds in Australia's Wylie Bay, taking 2020's unprovoked great white shark attacks to record numbers

Experts believe cooler water temperatures are behind an increased number of unprovoked and deadly suspected great white shark attacks since January - the highest for 86 years.

Dad Andrew Sharpe became the latest fatality after the surfer was killed in an attack on Friday at Kelp Beds in Wylie Bay, near Esperance, on Western Australia's south coast.

Father-of-two Andrew Sharpe was killed by a shark on Friday
Father-of-two Andrew Sharpe was killed by a shark on Friday
A La Niña weather event in recent months has made waters more favourable for great whites, drawing them into shore, say scientists.

The Taronga Conservation Society's Shark Attack File has deemed six such incidents as unprovoked, while one, in July, was provoked.

Gary Johnson, 57, died after he was attacked while diving with his wife near shark hotspot Esperance in January.

Zachary Robba was swimming off the Great Barrier Reef in Queensland in April when the wildlife ranger, aged 23, was killed.

Rob Pedretti, 60, was boarding at Salt Beach near Kingscliff in northern New South Wales two months later when he was mauled to death.

Matthew Tratt was killed in a suspected great white attack on Queensland's Fraser Island in July - with the 36-year-old spearfishing, which is considered 'provoking' sharks as they are attracted by the blood.

The same month, teen surfer Mani Hart-Deville, 15, was killed in another suspected great white attack at Wooli Beach, near Grafton on the New South Wales north coast.

Finally, 46-year-old Nick Slater was killed by a suspected great white while also surfing at Greenmount Beach on the Gold Coast last month.

TCS's Dr Phoebe Meagher told the Daily Mail this year's fatalities are six times the average.

Dr Blake Chapman, who specialises in shark neuroscience, said great whites follow migrations of prey like salmon, which prefer cooler waters.

She told The Guardian : "We do tend to see little spikes in shark bites in La Niña.

"For great white sharks, if we see them bite someone once and then leave, it suggests they were maybe curious and weren't in the area for prey, because there is nothing stopping a shark from eating a person," the expert added.

There have been a total of 17 unprovoked shark attacks this year, 18 in 2018 and 22 in 2015 - but the last time such incidents led to six or more fatalities was 1934.