The WA Government has canned its SMART Drumline trial after use of the technology only resulted in tagging two of the target white shark species in two years.
The $6.4 million trial was located off the coast of Gracetown in the state's southwest to determine if the non-lethal technology would reduce shark attacks in WA.
The government agreed to the trial after a community campaign was launched when two people were attacked by white sharks in separate incidents at Gracetown on the same day on April 16, 2018.
The presence of sharks in southwest waters had also resulted in the cancellation or disruption of major international sporting events in the region including the Margaret River Pro and Ironman in Busselton.
An independent review of the trial by WA's chief scientist professor Peter Klinken found that SMART drumline technology was not effective at catching white sharks.
Professor Klinken found the technology provided no demonstrable value in reducing the potential risk posed by white sharks off the South-West coast.
The trial began in February 2019, and at the end of first year only two white sharks had been caught, because there was not enough data to make a decision he recommended that they continue the trial.
"After two years there was still only two white sharks that were caught and tagged, so my analysis was that there was hundreds of different sharks lots of tigers, makos and whalers but they hadn't caught any whites," he said.
"Some people would say it has been a failure but I would say it hasn't been a failure, these drumlines have told us they haven't caught white sharks.
"People could argue there weren't many white sharks in the vicinity, while that is not an unreasonable thing to say, what was really surprising in the study was sharks that had been tagged in other locations including the Eastern States went through the acoustic bouys setup around Gracetown, Yallingup, Bunker Bay and Meelup."
Professor Klinken said during the trial they were able to record unexpected information about how sharks moved through the area, how close they were to shore and where they moved to next.
"Importantly, eight white sharks went through when the drumlines were in the water," he said.
"These were sharks that had been previously tagged, baits were in the water and they were not attracted to them.
"If eight tagged sharks were not attracted to these baited drumlines, how many untagged sharks went through as well?
"To me the ultimate conclusion was the drumlines were not an effective way to tag sharks and they were not a great deterrent for mitigating risk."
'Serious swimming machines'
Professor Klinken said some of the findings in the trial were "wild" because there was a theory that there were two populations of white sharks in Australia that inhabited either the East Coast or West Coast.
"A whole bunch of white sharks came over for a holiday from the east to visit us here in the west," he said.
"The other thing that was really interesting was the two sharks that were tagged travelled enormous distances.
"The first one, the big one which measured about 4.5 metres, travelled close to 1,500 kilometres in 50 days ending up in Esperance.
"The smaller one ended up going all the way up to Shark Bay, almost to Carnarvon, then came back went past Gracetown did a loop, went around the back and ended up in Esperance.
"The shark swam 5,500 km in 200 days.
"These are serious swimming machines, both sharks averaged one kilometre an hour every day, 24/7.
"Most of the time they were out in deep water, every now and then they would come in then go back out again.
"There was so much good information to get out of the trial it was phenomenal."
Criticism of the SMART Drumline trial
WA's SMART Drumline trial did not go without criticism with some saying that it did not entirely replicate the trial in NSW which has shown more success in catching and tagging white sharks.
Vasse MLA Libby Mettam said the state government failed to consult with the NSW Government, which had the largest shark tagging program in the world.
"Issues that they have failed to replicate from the NSW trials included bait, target species and the number of VR4 receivers which provide real time alerts ensuring the public are aware of tagged sharks in the area," she said.
Professor Klinken disagreed saying they tried to bring the trial as close to the NSW program as much as possible.
"They were different trials that were going on in NSW," he said.
"One of them was very close to a great white nursery so they were getting lots of tags, but in another area they were getting roughly the same number as us and were more random.
"I don't think it is a fair criticism."
Professor Klinken said the targeted approach used by the DPIRD was more successful in tagging white sharks off WA's coastline than SMART Drumlines.
"They have managed to tag 51 great whites over a period of 143 days compared to Gracetown, which tagged two sharks over 440 days," he said.
"If a whale carcass is known to be floating around somewhere it is likely to attract whites, so the DPIRD go into that area and try to set lines for the whites using exactly the same bait that was used in the Gracetown trial.
"In the targeted approach, it is used where there will be a concentration of sharks because they are there for a whale carcass, that is the difference."
State government invest millions into 4-year shark mitigation methods
WA's SMART Drumline trial at Gracetown will conclude on May 20, 2021 with an additional investment of $2.8 million being made into methods which have been more effective in tagging white sharks, as well as upgrading the Shark Monitoring Network.
The State Government will increase its investment in further successful initiatives to enhance public safety, including:
- upgrades to expand the detection range of WA's tagged shark monitoring receivers;
- support for beach enclosures at popular beaches, and;
- continuing the rebate scheme for personal shark deterrent devices for surfers and divers.
Fisheries Minister Don Punch said while the risk of a shark attack was low, the investment would ensure water users are better informed than ever on the movement and whereabouts of white sharks.
"Thanks to the hard work of all involved in the trial, we now have scientific evidence establishing SMART Drumlines are not effective at catching or reducing the potential risk posed by white sharks, and funding can be redirected to expand demonstratively effective shark mitigation initiatives to keep ocean users as safe as possible."
Professor Klinken said DPIRD did a good job in designing the trial and engaging with the community and stakeholders.
"The contractors did an outstanding job in being able to get out 70 per cent of the time in huge swells and the wild weather that happens in Gracetown," he said.
"They were awesome in their ability to deploy the SMART Drumlines, then to get to any sharks that activated the drumlines in 11 minutes.
"In the two years of the trial hundreds of sharks were caught and not one shark died in that whole process."