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A message from the deep
23 December 2010
Lifesavers on Adelaide’s suburban beaches could one day receive warnings of sharks in the area via text messages to their mobile phones.
A research project being led by shark ecologist Dr Charlie Huveneers and colleague Paul Rogers involves the placement of electronic receivers on the seabed off Adelaide’s beaches which record signals from sharks that have been tagged with acoustic transmitters.
Dr Huveneers says that at present the information recorded is stored on the receiver before being recovered by the researchers every six months or so and physically downloaded to a laptop while at sea.
The data is already providing valuable information about the movement of nine sharks that have been tagged in the Gulf of St Vincent.
However, Dr Huveneers – whose position is jointly funded by the South Australian Research and Development Institute (SARDI) and Flinders University – is particularly excited by the potential of the latest receiver technology.
He says the new receivers take data from the transmitters on the sharks and generate a text message which can be sent to mobile phones.
“Conceivably in the future, we could see lifesavers on station on the beach receiving information about the presence of a shark in real time. Such a scenario, while limited by the number of tagged sharks, could significantly boost beach safety,” he said.
Standing on the back of a boat attaching acoustic tags to very large sharks as they are lured nearby is a long way from the stereotypical image of an academic researcher.
For Charlie Huveneers, a wetsuit has replaced a laboratory coat and he gets up close and personal with sharks, both above and below the waterline.
Originally from Belgium, Dr Huveneers was introduced to Australia’s marine life when he visited Maryborough, Queensland, as a teenage Rotary exchange student in 1998–99. The country made a lasting impression. He subsequently returned to complete a PhD at Macquarie University in NSW after studying oceanography and marine biology at Southampton University in the United Kingdom. It was during his undergraduate and honours studies that Dr Huveneers developed his interest in sharks, and field work in the Bahamas, South Africa and England followed.
Dr Huveneers joined Flinders and SARDI Aquatic Sciences in March 2009, and has been involved in a range of research programs that extend from Adelaide’s suburban beaches to Port Lincoln and South Africa.
During the 2010 summer, Dr Huveneers and his team will attempt to tag a further 11 bronze whaler and dusky whaler sharks in Adelaide’s metropolitan waters.
The sharks are caught on longlines using short soak times and circle hooks to reduce gut hooking and increase survival rates. The researchers then take advantage of ‘tonic immobility’ which occurs with whaler sharks when turned on their backs – they become placid, almost going into a sleep-like state – to surgically implant an acoustic transmitting tag inside the shark’s peritoneal cavity. Released back into the ocean, the sharks will reveal their movements to researchers for up to 10 years. The researchers have installed 26 receivers off Glenelg, Grange, Semaphore, St Kilda and Long Spit.
“We need to understand more about the biology and movements of bronze and dusky whaler sharks in South Australian waters if we are to plan effectively for the conservation of this species while, at the same time, enhancing the safety of beachgoers,” Dr Huveneers said.
In another research project, Dr Huveneers’ team is collaborating with SA cage-diving operators in a world-first project to ensure the State’s ecotourism activities take good care of Australia’s protected white sharks.
By mid-December, the team had tagged ten white sharks which inhabit the area around Australia’s main cage-diving operations off the remote Neptune Islands, 75 kilometres from Port Lincoln, in a project which aims to understand how sharks react to berleying activities over time.
“Berleying has been increasing as cage-diving becomes more popular but the impact of this activity is still poorly understood, and there is a need to investigate how berleying might affect white shark behaviour and movements,” Dr Huveneers said.
The white shark cage-diving industry at the Neptune Islands attracts a large amount of tourism to South Australia and Port Lincoln. It is important to ensure that this industry is sustainable and that it does not negatively impact on the white shark population,” he said.
Dr Huveneers’ contribution to enhancing knowledge about sharks – a species that seems to inspire fear and fascination in people in equal measure – was recognised with a Tall Poppy of Science Award in 2010.
• Information obtained from Flinders University Encounter magazine
