The Makers of Shark Shield Hit Back
Earlier this month the South Australian newspaper, The Advertiser, broke a story that brought into question the efficacy of electronic shark deterents. The story followed a series of tests that were carried out in South Australia and South Africa, the results of which were kept private. Using Freedom of Information laws South Australian politician, Robert Brokenshire, forced the publication of the results and an associated video. It was this information that formed the basis of the Advertiser story (which was also subsequently published on Swellnet).
Amanda Wilson is the Managing Director of Shark Shield, the company whose products were being tested and hence now being publicly questioned. She strongly disagrees with the media's interpretation of the results and spoke to Swellnet about it:
Swellnet: Dr Charlie Huveneers stated that the test results weren't disclosed as the findings may be misinterpreted by the public. Were the test results always intended to be kept private? Amanda Wilson: The privacy of the test results is actually controlled by SafeWork SA and the South Australian Research & Development Institute (SARDI). These are the organisations that commissioned the research, carried out the research, prepared the report, and therefore own the report.
Please note that ABC News has already written several stories about the SARDI testing several months ago. The test results have also been discussed in the scientific and marine research fields. I have also advised all of our sellers/distributors around the world about the testing. So people are well aware of the testing.
We agree with Dr Charlie Huveneers comments that the public could misinterpret the results, and the recent misleading News Ltd article is a great example of this. People should have a proper understanding of electronic shark deterrent technology before they can assess the report and come to a conclusion. A Shark Shield is a life saving device so the consequences of making a decision based on misinterpreting information or reading misleading news stories or blogs etc can place lives at risk when an effective solution is available.
Unfortunately, there has already been a situation like this where a coronial enquiry found that a fatally attacked diver had access to a Shark Shield but did not wear it because they felt pressured by the dive group leader who did not believe in the product. At the end of the day the technology works, so we don't want people being misled like for example when microwave ovens were introduced. It was rumoured that they ruined food when in actual fact they didn't. Technology adoption was slowed by a myth.
Were you surprised by some of the test results or the vision in the video? The test results prove that the Shark Shield technology reduces the risk of shark attack and I think it's important to discuss the complete SARDI testing, rather than make a conclusion of a 57 page test report by viewing a very short video.
The SARDI testing comprised of three different test setups on the FREEDOM7 model Shark Shield. The tests comprised of a dynamic test where a seal decoy and a Shark Shield were towed behind a moving boat. Also a static test where a bait was suspended near a Shark Shield. And finally a test to ascertain whether a Shark Shield attracts sharks.
It should be noted that the test conditions were extreme, as a Shark Shield user would not find themselves in a similar situation, so this needs to be taken into consideration when reviewing the results. For example, with the static testing, a Shark Shield user would not find themselves in burlied water off of Neptune Island South Australia, an island known for its seal colony and shark cage diving industry, with a 6kg section of Bluefin Tuna attached to themselves. Also with the dynamic test, a Shark Shield user would not find themselves being towed behind a boat at 8 knots near Seal Island off of South Africa, which is where a large seal colony is located and also where tour operators tow seal decoys to get white sharks to breach.
Even in these extreme conditions, the Shark Shield increased the average time the static bait was take by 100% (from 122 seconds to 244 seconds). In the dynamic testing, the Shark Shield reduced the total number of breaches (16 when turned off to 0 when turned on) and surface interactions (27 when off & 2 when on).
Why do you think there was a difference between the results on tuna bait and decoy seals? The test results were different because of where the bait was located with respect to the Shark Shield's electrical field. In the static test the bait was located to the edge and/or outside the Shark Shield electrical field. In the decoy seal trials the shark had to travel "through" the field to reach the decoy, and as the research showed, it did not. Note that in the testing published in the research paper by Smit, C.F. and V. Peddemors. 2003. Estimating the probability of a shark attack when using an electric repellent. South African Statistical Journal 37: 59-78 the bait was placed in the centre of the electric field strength, these test confirmed without doubt the devices deterrent capability.
A lingering criticism of electronic devices is that they may attract inquisitive sharks. How do you counter that criticism? Have Shark Shield ever tested to see if the theory may be true? SARDI tested this theory in their recent testing and found no evidence to prove this occurs. A Shark Shield does not work by emitting a Radio Frequency signal, which people may associate with long distance communication through the air. A Shark Shield produces a localised protective electric field with a high power pulsing current that flows between two electrodes that are housed at each ends of the antenna in the SURF7 or FREEDOM7, or between the ankle and tank electrodes for the SCUBA7 model.
Sea water is a poor conductor therefore even though the Shark Shield produces a considerable protective electric field due to its high power, large distance between electrodes, and large surface area of electrodes, the field strength dramatically reduces every metre out from the source. The result is a very localised electric field.
At the end of the day a shark would detect a person in the water with its longer range senses i.e sound, smell, pressure, and vision, rather than its very close range electrical sensing.
Do you think some people have an incorrect idea of the role and also the effectiveness of Shark Shields? Some people incorrectly think that a Shark Shield allows them to swim long periods of time with a shark. Even though other tests for example have shown a Shark Shield has repelled white sharks for the whole day of testing eg 24 x 10 minute approaches, we don't want the user to stay in a life threatening situation so we always recommend the user gets to safety once a shark is sighted.
There are a handful of people that have the mindset that if we can't guarantee our product will stop a shark in all situations then the product is no good, however we like to compare our technology to a car seatbelt, it's a proven safety solution, not a guarantee. We have many Shark Shield users that have provided positive testimonials about Shark Shields and believe that their Shark Shield has indeed saved their lives.