Great white and grey nurse shark movements revealed

Great white (top) and grey nurse sharks.

NSW scientists are a step closer to understanding the complex behaviour of great white and grey nurse sharks, with results of tagging research now being analysed in detail.

In the latest research effort Department of Primary Industries scientists tagged 3 great white sharks and 8 grey nurse sharks in a bid to learn more about their behaviour.

DPI Senior research Scientist, Dr Nick Otway, said this is dangerous but vital work - this information will better inform us about how to save these sharks from extinction as well as better educate the public on safer swimming.

"The tagging research project used two state-of-the-art technologies - satellite tags and acoustic tags.

"The juvenile white sharks were tagged off Stockton beach with the assistance of commercial and recreational fishers.

"Scientists were then able to follow their movements. For example, a 2.3 metre female great white swam north to Big Seal Rock, she returned to Stockton Beach 2 weeks later where she remained until early November. She then left Stockton Beach and swam north arriving at Fish Rock (off South West Rocks) a month later.

"A male great white shark also spent time off Stockton Beach, before migrating north to Fish Rock, where he remained for more than a month. This is the type of information we are getting, Dr Otway said.

The grey nurse sharks were tagged with the assistance of recreational scuba divers, at Fish Rock off South West Rocks on the mid-north coast of NSW.

"Of the grey nurses tagged, a male migrated north, covering at least 400 kilometres in about 3 months. In contrast, the two females tagged at the same time did not undertake the same northerly migration. Instead over the same three months they only swam 120 kilometres from Fish Rock," he said.

"Interestingly male and female grey nurse sharks tagged at a different time at Fish Rock all migrated south. Two of them swam about 600 kilometres south to Bateman’s Bay.

"The movements of the sharks were confined to waters with temperatures ranging from 14 to 26 degrees Celsius."

70 acoustic listening stations, which are part of a system known as SEACAMS (South East Australian Coastal Acoustic Monitoring System), have now been installed by DPI on the seabed at many locations along the New South Wales coast to monitor the movement patterns of the sharks.

Unlike other tagging projects, the listening stations monitor the sharks continuously without the need for human contact.
Over the past few years DPI scientists have fitted great white and grey nurse sharks with electronic ID tags which also transmit the swimming depth of the sharks using sound waves.

It is hoped the monitoring will help establish the migratory paths and provide detailed information on the localised movements of these sharks at various sites along their migratory routes.

Each of the listening stations features an acoustic receiver and a temperature logger. The receiver records the identity of the shark, the depth at which the shark is swimming and the time of detection.

A reward of $100 is offered by NSW DPI for the safe return of a pop up satellite tag.

GNS pop-up tag map

GWS pop-up tag map