Science Gone Wrong Blamed For Shark Injury

February 9, 2007

Release from: Renee Konig
Bateman's Bay Post

THE CSIRO has downplayed the seriousness of a grey nurse shark injury, according to a Batemans Bay diver.

Divers spotted the grey nurse shark swimming in South Coast waters about four weeks ago, and realised something was seriously wrong.

Diver Wayne Smith suspected a CSIRO tag designed to monitor shark behaviour was either not made with the right materials, or didn't break down when it was meant to. Consequently, barnacles have attached to the tag, generating large growths and ulcers.

Mr Smith is very upset by the situation.

"They are already endangered as it is, with only 260 to 300 left in the wild," he said.

The CSIRO suspects one of their acoustic tags caused the injury. The tags are small devices that transmit a unique code about once a minute.

This code can be detected by moored listening stations, which then record when tagged sharks arrive at a monitored site, how long they stay and when they leave.

Such tagging is a common method for examining growth rates, movement patterns, and for estimating population size.

"We would hope that most of the sharks we tagged would have dropped their tags by now," said Barry Bruce from CSIRO.

"However, it is clear that despite all our attempts to minimise any untoward effects, this hasn't been successful for all the sharks."

Mr Bruce said, despite the obvious growth and cuts on the skin, the shark appeared to be healthy and behaving normally.

Dr Nick Otway, from the Department of Primary Industries, agrees.

"I'm 100 per cent sure this shark wouldn't be in any distress whatsoever and will heal easily," he said.

Mr Smith believes the shark's injuries are being underestimated, and is not at all pleased.

"There are large ulcerations on the skin and the lateral line is under serious threat of being damaged," he said. "It's like sticking a pin in your leg and asking you to walk around with it for three years."

Mr Smith also believes there are enough other activities endangering grey nurse sharks, without adding "tagging gone wrong" to the list.

He said set-line and recreational fishing were the biggest problems at the moment.

"It's one thing to lose fish to recreational and set-line fishing, but it's another thing for us to lose sharks because of scientific research, it's a horrible thought."

Dr Otway will be sending down a cutting tool to remove the shark's tag. Mr Bruce claims the CSIRO has no further plans to tag grey nurse sharks until a solution is found.

"We have, since identifying the issue, been working with our electronics and workshop teams to design a programmable electronic release for these tags to avoid this problem in future," he said.