The tagging of a huge five-metre white pointer in King George Sound has presented a potentially huge breakthrough in shark research and a triumph for local Fisheries staff.
The massive female great white, estimated to weigh about 1.6 tonnes, was the biggest ever internally tagged in Australia, and one of the largest in the world.
The shark was measured at 5.04m to the fork in its tail, suggesting an overall length of around 5.3m.
[Shark Monitoring Network project manager Mark Kleeman said internally tagging a white pointer of this size was almost unprecedented.]
Shark Monitoring Network project manager Mark Kleeman said internally tagging a white pointer of this size was almost unprecedented. Photo: Scott Coghlan
It took three Fisheries staff two-and-a-half hours to subdue the shark, which was hooked close to Mistaken Island in around 15 metres of water on Sunday, March 30.
The same shark had been externally tagged the previous Wednesday when it approached a Fisheries vessel close to Limestone Head, and then set off receivers at Ellen Cove on the following Thursday and Friday, leading to beach closures.
The great white took a salmon bait, culminating in it being fitted with an internal tag to help monitor its movements for up to 10 years.
Shark Monitoring Network project manager Mark Kleeman said internally tagging a white pointer of that size was almost unprecedented and a cause for celebration.
"This is very exciting and potentially a world first," he said.
"It is something we have been striving for and it is great to prove we can handle an animal of that size.
"The main thing is that tracking larger animals opens up a whole new world.
"Lots of juveniles have been tagged, but to have a fully-mature female and get 10 years of data out of it is a big thing for us.
"We are excited by the potential of what this shark can give us."
The shark was caught using 14-16mm rope attached to 3mm cable, and a hook considerably smaller than that with which Premier Colin Barnett infamously posed a few months ago.
After the shark was finally subdued, Fisheries staff had to attach three ropes around it and roll it upside down.
However, once it was upside down the shark went into a state of "tonic immobility", similar to being asleep.
That enabled Fisheries workers, aboard a 6m vessel not much bigger than the shark, to make a small incision in its stomach without lifting it out of the water and insert the tag.
The whole process took about five minutes.
Mr Kleeman said only about 340 sharks of various species, including a small number of white pointers, had been tagged in Australian waters.
While there has been so much attention on the drum line program off the west coast, Fisheries staff in Albany have been putting in long hours to quietly tag these sharks, which are around in good numbers at the moment, possibly due to the salmon schools in the area.
However, it did not make them easy to catch.
Mr Kleeman said there had only been five great whites tagged in Albany over the last 12 months and 17 along the south coast since 2009, making each successful tagging significant.
When this newly-tagged great white comes close to the network of receivers dotted along the southern WA coastline from east of Albany to Ocean Reef, Fisheries will receive instant notification of its location.
The shark remains in King George Sound. It set off receivers again earlier this week. Beaches were reopened on Tuesday.
"We will be able to see where it is travelling and how often," Mr Kleeman said.
"We will get a good picture of the movements of this particular animal.
"Over time we will be able to build the data and then we can see if there are any patterns forming, which is a great start for understanding more about them."
The satellite-linked network is part of a long-term project to help scientists better understand the movements of tagged white sharks through WA waters as well as improve safety at Western Australian beaches.
Along with the satellite-linked receivers, there are also more than 320 seabed monitors located off various parts of the WA coast which also record movements of tagged sharks.
External tags on great whites usually only last around two years, making internal tags the preferred option.
Mr Kleeman said it was believed female great whites didn't mature until 15-20 years of age, with this shark estimated at being more than 30 years of age.
"It is the first one we have caught of breeding size," he said.
"It had signs of mating scars, with bites down one side."
They also took DNA samples from the shark to enable researchers to study genetics, with the east and west coast appearing to have separate populations.
Mr Kleeman said it was interesting the shark set off the receivers near Middleton Beach at 4.41pm on Thursday and 4.42pm on Friday, possibly suggesting a pattern of behaviour.
He asked anyone who saw a great white report it to the water police immediately on 9442 8600, as sighting reports from members of the public remain a vital contribution to coastal safety.
- The Great Southern Weekender
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