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Smile, you're on shark cam

SCIENTISTS are planning to use baited, fixed cameras to film bull sharks in Sydney Harbour and the Georges and Hawkesbury rivers to establish whether they inhabit Sydney's urban waterways permanently and the level of risk they pose.

Leading marine researchers are behind the controversial proposal, which has the initial financial support of the NSW Department of Primary Industries and the Sydney Aquarium Conservation Foundation but needs approval from the Australian Research Council.

As part of the proposal the sharks would be filmed from four cameras rotated through the three waterways. Up to 30 juvenile bull sharks would be acoustically tagged as well and tracked by boat through the estuaries.

Since 1791 there have been 30 shark attacks in Sydney Harbour, with a peak between 1910 and 1920 and a decrease since then due partly to netted harbour beaches. The last fatality was in 1963.

In February 2002, Paul McNamara, 35, was forced to clamber onto a buoy and flag down a passing fishing vessel after a bull shark reportedly knocked him from his kayak near Cabarita Marina, on the Parramatta River.

Two months later, fishermen hooked a three-metre bull shark in Rushcutters Bay.

Since then, bull sharks have been sighted everywhere from Rose Bay to Lake Macquarie and Throsby Creek in Newcastle.

The species has been blamed for two deaths over the past five years in Gold Coast canals.

Associate Professor Iain Suthers, from the Sydney Harbour Institute of Marine Science and the University of NSW, said some controversy existed over whether bull sharks lived in the waterways or migrated seasonally, or whether it was a different shark species altogether.

The proposed three-year research project could pinpoint the areas the sharks favoured and when they used them.

Professor Suthers said cam-corders were encased in 30 centimetre-long water canisters built from PVC. The pipes had a window cut into them to allow full view of surrounding sea life. These cameras, which were baited with pilchards, were used with great success in tracking fish and sharks in Jervis Bay and Lord Howe Island last year.

"The pilchards are an oily fish and are like butterballs for the other marine life; they love them," Professor Suthers said.

"The smell attracts the sharks who like to nose around the bag and this is caught on the film by the nearby camera. It's great to watch and learn."

Professor Suthers said he hoped to start the project in February next year when the estuary waters' temperatures increased past 20 degrees, when shark occurrence seemed to increase.

Two sharks were seen off Sydney beaches yesterday, Surf Life Saving Australia said.

At Frenchmans Bay, La Perouse, a four-metre shark was seen about 10.30 am. A search was later conducted but the shark was not seen again.

Swimmers were cleared from the water at Narrabeen before a three-metre hammerhead shark was herded out towards the open ocean.

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