Research

Shark Tagging

White sharks: Bruce and Lulu - first sharks in the cradle

Use of the 'cradle' to attach satellite tags to large white sharks was trialled by CMAR scientists at the Neptunes in March 2004, after similar techniques proved successful in South Africa.

A team from the Melbourne Aquarium, led by Craig Thorburn, helped to design and manufacture the cradle which secures the sharks next to the capture vessel. They also advised on the use of oxygen therapy for the sharks during the tagging process.

Two sharks (nicknamed 'Bruce', after the shark in Finding Nemo, and 'Lulu', named by Rolf Czabayski on a previous encounter) were fitted with CMAR satellite tags on 30 and 31 March 2004.

Bruce (male, 3.6 m, 400 kg) was estimated to be 8-9 years old. He lived up to his more famous counterpart by travelling east from the Neptunes, through Bass Strait and then north along the eastern Australian coastline to the Great Barrier Reef in southern Queensland where he spent the winter east of Rockhampton. In October 2004, Bruce returned south and the last position received (5 November 2004) located him in eastern Bass Strait. The recorded distance travelled by Bruce exceeded 6000 km during this seven-month period.

Despite being seen on the same day as Bruce and tagged on the following day, Lulu's travels were completely different. She headed east from the Neptunes, moving through Investigator Strait and into Gulf St Vincent, remaining east of Adelaide for several weeks before turning west and swimming across the Great Australian Bight. The last position received (18 October 2004) located Lulu approximately half way between Albany and Esperance on the southern coast of Western Australia.

The tags attached to both sharks continue to transmit, but their signal strength is low and positions are now rarely recorded. This indicates that their batteries are almost exhausted.

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