Testing of aerial drones to track the movements of sharks in Australian waters began Wednesday as the government admitted there was "no easy way" to protect swimmers from the predators.
The trials began at Coffs Harbour, on the mid-north coast of New South Wales state which has endured 13 attacks by the creatures this year, including one lethal mauling.
"There is no easy way to reduce risks for swimmers and surfers," New South Wales Primary Industries Minister Niall Blair said in a statement.
"We are delivering on a commitment to test the best science available, including new technologies, as we try to find an effective long-term solution to keep our beaches safe."
The drones are expected to feed live images back to an operator, including GPS coordinates, to better warn and protect people from shark attacks.
Blair said the trials were the first of several to be undertaken during the summer months, including testing "smart" drum lines which he said not only hooked sharks but alerted authorities who could then tag and release the animals.
Baited hooks attached to floating drums were used to capture sharks in Western Australia in 2014 after a string of fatalities, with the largest of the animals put down.
But the controversial catch-and-kill policy was later abandoned after objections from the state's environmental agency and conservationists.
The New South Wales government said its drum lines were more humane.
"They're like a baited hook that has technology connected to it so when the bait is taken, a message is sent to our vessels and they'll attend those lines immediately," Blair told national radio.
"They will then tag and release the sharks that are caught on those. So they're very different to the traditional drum lines which could have sharks sitting on them for days before they're checked."
Under a Aus$16 million (US$11.6 million) shark strategy, the New South Wales government will also boost helicopter surveillance over popular beaches.
It has also fast-tracked the delivery of two "listening stations" to be positioned on the far north coast of the state to provide real time tracking data of tagged sharks.
New South Wales, the nation's most populous state, has ruled out culling sharks despite the spike in attacks this year.
A Japanese surfer died in February after his legs were torn off by a shark and there have been 12 other serious attacks up and down the more than 2,000-kilometre-long (1,200-mile) NSW coast.
There were only three attacks in the state in 2014.
Experts say attacks are increasing as water sports become more popular and bait fish move closer to shore, but fatalities remain rare.
Sharks could reveal how neck disease forms in humans
New insights into how the neck vertebrae of elephant sharks naturally become fused could help researchers to understand how neck development can go wrong in people affected by disease.
In a paper published in journal PLoS One, researchers from Monash University's Australian Regenerative Medicine Institute (ARMI), Curtin University, the Natural History Museum, London and the Australian Synchrotron, investigated how the fused neck developed in elephant sharks.
In people with the disease known as Klippel-Feil syndrome, the vertebrae of the neck becomes fused, but in living sharks and rays, and in some fossil armoured fish called placoderms, having a neck encased in bone is normal.
Lead researcher, Dr Catherine Boisvert, ARMI, said knowing how this fused neck formed under normal conditions could be the first step in understanding how neck development can go wrong in people when affected by disease.
"In some animal species, part of the animal's body mimics what we see in a human disease. These species are known as 'evolutionary mutants', and analysing them provides unprecedented access to information in a healthy individual."
"We are gaining a better understanding on how these morphologies develop and what developmental pathways (genes and their networks) are involved in producing them. This knowledge may help us better understand the disease in humans.
The researchers grew elephant sharks collected from eggs laid in captivity on the Mornington Peninsula, Victoria. They stained them to study the fused neck, called the synarcual, and reveal cartilage and muscle development. They also analysed the fossils of placoderms, providing a high level of data on how this fusion occurred for comparison to living animals.
Using microscopic imaging at the Australian Synchrotron, the researchers found that neck vertebrae in the elephant shark and placoderm developed normally, and only later became fused after emerging from their egg. Skates and rays appeared to show a similar pattern, suggesting this may be a normal condition for vertebrate animals in general.
This contrasts the belief that a fused neck forms because individual vertebrae fail to form in early development.
Dr Boisvert said the next step is to look further into the genes that are responsible for this fusion in the shark species and apply them to diseases of the human spine.
The way the synarcual develops in placoderms and sharks is most similar to human disease Fibrodysplasia Ossificans Progressiva, which slowly turns soft tissues to bone - patients are born with a normal skeleton, with fusion occurring subsequently.
"Sharks don't have true bone - instead they have a hard kind of cartilage called prismatic calcified cartilage - and we don't fully understand yet if the vertebra fusion is due to overdevelopment of cartilage, or if the soft tissue between the vertebrae becomes transformed into cartilage, resulting in fusion," Dr Boisvert said.
"These sorts of 'metaplastic' transformations of the spine have been observed in farmed salmon, and exciting new research is beginning to unravel the genes involved in these transformations. Our goal is to do the same for elephant sharks, rays and skates."
"All in all, we are coming closer to understanding how a fused neck develops normally or under stressful conditions (as is the case for farmed salmon) in a range of vertebrates at the base of our ancestry."
Australia to test technology after wave of shark attacks
Australian shark experts will test cutting-edge technology—including electrical barriers powered by wave energy—following an "unprecedented" series of attacks on swimmers.
The country has one of the world's highest incidences of shark attacks and researchers from around the world met in Sydney on Tuesday at a meeting organised in part to address community fears.
"What we've seen is pretty unprecedented," New South Wales state Premier Mike Baird told the conference of a string of attacks in eastern Australia which left one dead and seven injured.
A Japanese surfer died in February after his legs were torn off by a shark but there have been other serious attacks up and down the more than 2,000-kilometre-long (1,243-mile) NSW coast.
There have been 13 attacks in the state so far this year, compared to three in 2014.
"Ultimately, we've moved from a position in some parts of the coast where the coastline was joy... (to) fear, and we need to take that away," Baird said, adding that his government hoped to test some of the recommended technologies during the upcoming summer.
"The decision-making process (to roll out the technologies) will be on the basis of the science... it will not be knee-jerk, it will not be in relation to any form of populist outcry."
Baird—an avid surfer who has ruled out culling sharks as an option—said he hoped experts would find ways to balance the need to protect humans against reducing the harm to marine life caught in barriers such as nets.
Deterrent technologies set to be reviewed include electrical barriers that can be powered by wave energy, as well as personal devices that surfers and swimmers can wear.
Detection methods include a smart drumline where sharks are removed from hooks before they die, and the "Clever Buoy", which uses sonar technology to search for shark-sized objects.
Marine biologist Daryl McPhee of Bond University, who helped the state government compile a preliminary list of options, said the recent innovations had increased researchers' understanding of shark behaviour.
"Sharks have seven senses. We don't clearly know how sharks completely sense their environment but we know much more than we did 10 years ago," he told AFP.
"We're able to use the information to potentially design better deterrence (technologies)."