Sydney’s bull shark heads north for the winter

by Industry & Investment NSW on 2 Apr 2011 A 2.5 metre bull shark tagged by Industry & Investment NSW (I&I NSW) researchers in Sydney Harbour has travelled over 5000 kilometres to locations as far as Lady Elliot Island and Townsville.

I&I NSW shark researcher, Dr Amy Smoothey, said the shark is providing a fascinating insight into the natural movements of bull sharks in NSW and along the east coast of Australia.

'This shark is one of 28 bull sharks tagged in Sydney Harbour over the last two years, ranging in size from 2.2 to 3.2 metres,' Dr Smoothey said.

'The shark was tagged with an internal transmitter in Sydney Harbour on 24 March 2009 and since then has been tracked by a series of underwater listening stations deployed throughout the Harbour and along the east coast of Australia.

'Last year the shark travelled from Fish Rock at South West Rocks on the State’s north coast to Sydney Harbour on 24 January 2010, before heading north again on 11 March 2010.

'The shark was then located approximately 2000 kilometres north of Sydney Harbour at Wheeler Reef off Townsville on 10 December 2010 and Lady Elliot Island on 23 December 2010.

'This year the shark was tracked heading south again and was last located off Port Stephens in January 2011.
'Why the shark travelled so far is still not clear, however, we will continue to monitor its movements to try and get a better understanding.'

Dr Smoothey said the bull shark is being tracked as part of the NSW Government’s efforts to minimise the risk of shark attack by unlocking some the secrets of Sydney’s bull shark population.

'As part of the research, so far this year, we have deployed over 1900 hooks into Sydney Harbour and tagged 17 bull sharks which we will continue to monitor closely to determine whether there are any predictable patterns in their movements over time,' Dr Smoothey said.

'We are particularly interested to see if there are any areas within Sydney Harbour that are favoured by the species, what times of the year the sharks visit the Harbour and whether factors such as water temperature and presence of bait fish, influence their movements.

'This type of research helps us understand movement patterns of sharks in and around Sydney Harbour and therefore assists in advising the public about where and when to swim.'

Swimmers are reminded that they can follow some simple, common sense tips to reduce their risk of an encounter with a shark.

These include:
• Not swimming at dusk and dawn
• Avoid swimming alone
• Avoid swimming when there are lots of baitfish around
• Avoid murky water

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