Scientists say shark deterrent does not deter sharks
SHARK researchers from the the University of Western Australia have released government-funded research into the effectiveness of a personal shark deterrent, known as the Electronic Shark Defense System (ESDSTM).
The research team travelled to Mossel Bay, South Africa, to test the effectiveness of the ESDSTM device with the large population of white sharks found in these waters.
The team recorded 395 encounters with 44 individual white sharks.
The research findings represent the most robust assessment of the effectiveness of the ESDSTM in deterring white sharks.
Personal shark deterrents offer the potential of a non-lethal solution to protect individuals from negative interactions with sharks, but the claims of effectiveness of most deterrents are based on theory rather than robust testing of the devices themselves.
The findings of this research showed that an active ESDSTM was no more capable of keeping sharks at a 'safe' distance than an inactive ESDSTM.
Sharks would routinely approach within 20-30 cm of the device, whether it was active or not.
The results were compared to an active Shark Shield deterrent (previously tested by the team using the same methodology), which effectively deterred white sharks by an average of 1.3m from the device.
Lead researcher Dr Ryan Kempster said that when in the presence of an active ESDSTM, sharks did show a reduction in biting, but this was countered by an increase in other, less aggressive forms of interaction, such as bumping.
"Although the effectiveness of the ESDSTM may vary between species, due to species specific differences in electro-receptive ability, the fact that white sharks are implicated in the majority of fatal incidents globally suggests that a device that cannot effectively deter this species should not be considered an effective shark deterrent," Dr Kempster said.
The research paper has been published in the journal PLoS One under the title Not All Electric Shark Deterrents Are Made Equal: Effects Of A Commercial Electric Anklet Deterrent On White Shark Behaviour.