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.
However,
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”
You can support our research,
education, and conservation activities by making a donation here.
-----------------------------------------------
Please share your thoughts about this article below.
Other Interesting Articles:
Disclaimer
Support Our Sharks posts articles and material
prepared by other organisations and individuals not affiliated with
Support Our Sharks for educational purposes. Support Our Sharks does not
necessarily agree with the opinions expressed in such material. Support
Our Sharks also provides links from this site to the websites of
featured news articles above for informational purposes only. The links
do not imply an endorsement by Support Our Sharks of these articles or
the content of their respective web pages.