BUBBLES will not keep sharks away and electrical deterrents like Shark Shields do not attract them, according to new University of Western Australia research unveiled by Premier Colin Barnett today.
Preliminary results of three research projects have been released, which Premier Barnett said have contributed a great deal to knowledge about sharks, shark detection and the effectiveness of some deterrent measures and led to the development of an advanced visual shark detection system.
The research was funded under the state government's $1.9 million Applied Research Program - Shark Hazard Mitigation which has sponsored eight research projects in total since December 2012.
Research teams led by Professor Shaun Collin, Director of UWA's Oceans Institute and former WA Premier's Research Fellow, and Associate Professor Nathan Hart have completed significant laboratory and field trials on existing electrical shark deterrents and potential novel shark deterrents such as loud underwater sounds, bright flashing lights and bubbles.
The deterrents have been tested in the laboratory and in the ocean in WA and South Africa on a wide range of shark species, including white sharks.
This evidence will shortly be provided to science journals for verification and must be regarded as preliminary until subjected to peer review.
Preliminary results showed:
- electrical deterrents do not attract sharks
- bright flashing (strobe) lights can be effective as shark deterrents and do deter a range of shark species from biting. However, the effectiveness of strobe lights appears to be restricted to strongly nocturnal and/or benthic shark species
- loud underwater sounds (both artificial sounds and natural orca calls) were not effective at deterring small sharks in the laboratory and were only a limited deterrent in the wild
- some bubble curtain arrays were effective in deterring sharks, but only for a very short time, after which the sharks become accustomed to the bubbles and did not hesitate to cross the bubble barrier. However, altering the presentation of the bubbles resulted in improved effectiveness in deterring sharks. Further investigation is needed
- the Shark Shield™ had a significant effect in deterring a range of shark species, including tiger sharks and white sharks, though further testing is required to be statistically confident in the species-specific effects
- the electric anklet device did not have a significant effect in deterring any shark species tested, including tiger sharks and white sharks
- laboratory research has led to the publication of 14 scientific papers mostly on the visual and electro-receptive abilities of shark species. This information is vital when designing deterrent systems targeted to interfere with those shark senses involved in attack.
Premier Barnett said it was important that UWA's results were scientifically validated through the peer review process before members of the public make decisions based on the research.
Full details of the research will be released in scientific publications later this year.
In testing the commercial shark deterrents, the UWA researchers developed new experimental apparatus that encouraged sharks to the bait while videoing how they reacted to the deterrent being tested.
The Premier said this shark deterrent testing equipment could become the standard by which existing and future deterrents could be tested and compared.
Professor Mohammed Bennamoun's team from the School of Computer Science and Software Engineering at UWA have also developed advanced computer algorithms that allow for the automatic detection, identification and tracking of sharks from aerial videos.
The system is powerful enough to distinguish sharks from other marine objects such as swimmers, boats and dolphins. The system also allows shark detection and tracking under challenging imaging conditions such as low light, strong sun reflections, poor contrast and fog.
The success of the research has also enabled the team to attract Commonwealth funding from the Australian Research Council with a five-year grant to continue research into automatic shark detection and tackle the more general problem of visual recognition of marine species. Automating marine species recognition would overcome a major bottleneck faced by marine scientists who currently need to manually process underwater imagery to assess the health of our oceans.
The Premier said the detection and tracking systems developed by Professor Bennamoun's team has the potential to enhance current shark spotting systems, assist marine biologists and possibly be adapted further for search and rescue.
UWA is also collaborating with WA's Shark Shield Pty Ltd on the field testing of their novel surfboard-based electrical shark deterrents being developed under another project in the State's shark hazard mitigation research program.
"Collaboration between industry and researchers is essential for the development, manufacture and marketing of effective shark deterrents. I look forward to the positive outcomes of this collaboration," Mr Barnett said.