Not All Shark Deterrents Are Made Equal
ESDS Fails Testing
Article by Support Our Sharks (11 Mar 2019)


Our latest research, published in the journal PLoS One, highlights the potential risk that the public face when they put their trust into untested shark deterrent devices.  

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. Therefore, there is a clear need for thorough testing of commercially available shark deterrents to provide the public with information on their effectiveness.

Our research team travelled to Mossel Bay, South Africa, to test the effectiveness of the Electronic Shark Defense System (ESDS)TM with white sharks (Carcharodon carcharias).  We observed almost 400 encounters with over 40 individual white sharks.

The findings of our research show that an active ESDSTM was no more capable of keeping sharks at a ‘safe’ distance than an inactive ESDSTM, as shown in this video. Sharks would routinely approach within 20-30 cm of the device, whether it was active or not.  Compare this to an active Shark ShieldTM deterrent (previously tested by our team using the same methodology), which effectively deterred white sharks by an average of 1.3 m from the device.

Shark Biting Active ESDSHowever, it should be noted 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.

Overall, we found that the ESDSTM showed limited meaningful effect on the behaviour of white sharks, as any effect that the active ESDSTM may have been having was at such a short range that sharks would likely have only experienced it if they were close enough to bite the device itself.  Thus, given that the device is designed to be worn on a user’s ankle, it would leave most of their body completely unprotected.

Lead researcher, Dr. Ryan Kempster, said “although the effectiveness of the ESDSTM may vary between species, due to species specific differences in electroreceptive 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.”

“Given the very short effective range of the ESDSTM and its unreliable deterrent effect, combined with the fact that shark-bite incidents are very rare, it is unlikely that the device would significantly reduce the risk of a negative interaction with a white shark.” Dr Kempster said.

“This research provides quantitative evidence of the ineffectiveness of the ESDSTM, its influence on the behaviour of white sharks, and an accurate method for testing the effectiveness of shark deterrents that future research should adopt.”

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

This research involved scientists from Support Our Sharks, the University of Western Australia, Macquarie University, and Oceans Research in South Africa.

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