Tracking Sharks On Nemo's Highways

November 28, 2006

Release from: Selina Mitchell
The Australian

Electronic underwater ears are being used to collect data on grey nurse and great white sharks in an effort to protect the endangered animals.

The sharks have been monitored for a number of years using satellite and sound-wave tags, but now the NSW Department of Primary Industries is also using listening devices at 60 sites along the coast from the Queensland to Victorian border.

The tags supply an individual identity code for each animal and information about water depth and temperature. The listening devices add critical information, noting immediately the whereabouts of sharks.

"We can find out about local movement in three dimensions when we use the tag information and the listening device information," NSW Department of Primary Industries senior research scientist Nick Otway said.

"We can gather information on the amount of time an animal spends at each location, and their movements in depth," he said. "We're gaining a good understanding of their movements and a better understanding of how they're using the sites at different times of the day and at different temperatures.

"Maybe they are following highways, Nemo-style. If they are, we hopefully will be able to find out."

The battery-operated devices were attached by divers with poles, and will be replaced every nine months.

NSW Primary Industries Minister Ian Macdonald said the listening stations monitored the sharks continuously without any need for human contact, unlike other devices.