Shark Deterrent Technology: Hear the facts. You decide.

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SharkShield

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With such heated debate about the conservation of sharks, and the natural desire for safety in our waters, the use of shark deterrent technology has become a necessary conversation that we simply must have. There is much speculation about the offered products, and for those that have that amphibious streak, there are a few pressing questions that are being asked: Does this technology actually work? How does it work? And does it attract sharks and then deter them? Could an electronic deterrent device, such as Shark Shield Freedom 7, be the new-found legend in our waters?

Firstly, a shark deterrent has to be one that has the capability of producing a low frequency that disturbs the electro reception in a shark. Here is where the scientific hat must be worn, because to understand how the deterrent technology works, there has to be some understanding of what we are trying to deter, and for that matter, protect.

All Chondrichthyans: sharks, rays, skates and chimeras, have Ampullary receptors in their heads, these are broadly tuned to low-frequency fields of <0.1–25 Hz, and believe it or not, these are the same electroreceptors that Australia’s beloved Platypus and Echidnas have. They all use them for the same thing, to find prey hidden under wet sand, to communicate to each other, to find a mate when the mood beckons, and to detect potential predators. This sensitivity is only operational when in close proximity, it is the final stages of detection for them all, including our sharks.

This is where it gets very interesting, Shaun Collins, a world expert on, ‘Electroreception in Vertebrates and Invertebrates’ (Collins et al) reports that all of the research on the many animals that have ampullary or tuberous organs, keeping in mind that this enables them to detect weak electrical fields, be it low or high frequency, only use it after they have used chemoreceptive, mechanoreceptive and their vision to localize their prey. In laymen’s terms, they detect particles in the water, vibration in the water, what is seen and then, the ampullae/mucus gland kicks in at a close proximity, and this is when an electromagnetic field is detected. As the waves emitted from an electromagnetic field do not travel great distances under water, and the sharks Ampullary receptors only fire up when it is close to its prey, it is an impossibility that this shark deterrent technology attracts sharks. This is because by the time the shark senses the electrical wave, he has a pain that travels like lightening through the gel in the receptors in his head giving him a headache of whale proportions which has him fleeing for calmer waters.

Shark deterrent technology is basically two electrodes that emit an electromagnetic field in a low frequency that interferes and greatly disturbs the shark’s electroreceptor. The extensive research, in fact over 20 years of it by the Zwazulu Natal Shark Board in South Africa, patented a successful model, which subsequently was thoroughly tested. The result, the sharks did not like it, and since then many organisations and private users have attested to its obvious deterrent capability. The reason the deterrent works is that it creates a low frequency that specifically targets sharks, but note that for full protection the electrodes need to be far enough apart to create an electrical field that surrounds the user. Electrical waves do not travel far under water so it is also crucial that the device is powered sufficiently to create an electrical field at least three or five meters in diameter.

The scientific jargon can sound very bewildering, yet a desire to gain trust and some hope in something tried and true, for the safety of all seems very necessary. So with this, steps toward assurance continue in the water itself. The original technology was released onto the market in 1995 by POD Holdings Ltd, a joint venture company partly owned by the Zwazulu Natal Shark Board and the South African Government. In addition to being tested by National Military and other authorities, Shark Shield has been extensively tested to the highest standards by scientists and marine biologists over many years.

The accumulative years of research by scientists and world-recognized organisations cannot be wrong, nor can the fact that the Shark Shield product has been used well over a decade by professional divers, the U.S Coastguard, the American and Australian Navy. This product must be seriously considered as a safety device in the water, just as wearing a seat-belt in a car is a safety choice. If it has kept this many citizens safe, and our Navy will not dive without one, then the message seems loud and clear. If the product conforms to what science knows works, and be aware that not all of the electric shark deterrents do, so do your research, then this seems the way to real conservation. True, conscious conservation of the ones we love and of sharks. The immediate and accessible solution, and the answer to the question must be that this product is the new legend in the water.
 
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Thank you, for the facts. However my humble opinion is that facts alone are not going to cut it with the scuba community. I free dive with a Freedom 2 in False Bay South Africa, however if I boat dive or dive with a scuba schools in false bay I get a very frosty reception to my shark shield, so much so that I do not use it at all. The inference is we want to see sharks (I Don&#8217;t not a Great White at any case unless on my terms) or you are so unlikely to be attacked by a shark as to make it pointless! I would love to hear some other opinions from the scuba community. My free dive buddies would not be seen dead without their range of sharkshield products from freedom 2 to freedom 7&#8217;s.

I await some comments on this eagerly.
 
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I have seen this on boats from time to time and I have at least two questions:

How does it affect other marine animals, especially at close range?

In fact, since I actively seek out sharks and rays to photograph them, will this inhibit that endeavor?
 
From their website


WARNING

We encourage people to wear Shark Shield when working in or enjoying the ocean to minimize the risk of shark attacks, but sharks can be dangerous and often unpredictable creatures. While extensive testing has been done and great care taken to develop and manufacture the Shark Shield range of products, it is impossible to guarantee that all sharks will be deterred under all circumstances. Water based activities in the presence of sharks is inherently dangerous and is not recommended therefore we recommend that if a shark is sighted that the user leaves the water
 
I don't see this as a great thing for scuba. Unless there is an on off switch? Because I would think that the field would turn on quite quickly if one were to find themselves in an (unlikely) situation.

I can see the benefit for spearos and surfers and free divers. Swimmers too, to an extent.

I too would like to know its effect on other marine life.

A thought, theoretically could this be used on a larger scale to protect beaches so we can get rid of the nets? I'm not thinking more power here, more like a grid.

Another thought with regards to whale sharks and shipping lanes. It'd be interesting to see if a beam of sorts projected from the bows of large ships would deter the whale sharks away?

Neat stuff.

With regards to conservation... I am not sure personal shark zappers will do much for the big picture. Anything is better than nothing though, AS LONG AS THE COMPANY DOESN'T PERPETUATE FEAR TO SELL THEIR PRODUCT. Like the flipping "documentaries" on Disc and NatGeo have been doing.



From their website


WARNING

We encourage people to wear Shark Shield when working in or enjoying the ocean to minimize the risk of shark attacks, but sharks can be dangerous and often unpredictable creatures. While extensive testing has been done and great care taken to develop and manufacture the Shark Shield range of products, it is impossible to guarantee that all sharks will be deterred under all circumstances. Water based activities in the presence of sharks is inherently dangerous and is not recommended therefore we recommend that if a shark is sighted that the user leaves the water

Kinda a necessary warning to protect the company is it not? I'm no lawyer but I'd guess it'd be quite a risk to skip the disclaimer... If it was me I'd put it up even with exceptional science to back up my claim. I'd do the same if I were a producer of Bear Spray or the likes.
 
I don't see this as a great thing for scuba. Unless there is an on off switch? Because I would think that the field would turn on quite quickly if one were to find themselves in an (unlikely) situation.

I can see the benefit for spearos and surfers and free divers. Swimmers too, to an extent.

I too would like to know its effect on other marine life.

A thought, theoretically could this be used on a larger scale to protect beaches so we can get rid of the nets? I'm not thinking more power here, more like a grid.

Another thought with regards to whale sharks and shipping lanes. It'd be interesting to see if a beam of sorts projected from the bows of large ships would deter the whale sharks away?

Neat stuff.

With regards to conservation... I am not sure personal shark zappers will do much for the big picture. Anything is better than nothing though, AS LONG AS THE COMPANY DOESN'T PERPETUATE FEAR TO SELL THEIR PRODUCT. Like the flipping "documentaries" on Disc and NatGeo have been doing.

I can't see this thing being powered up to protect large areas without endangering marine life, or swimmers. And a beam projected from ships? Sonar is hard enough on cetaceans, now were going to supercharge the shipping lanes with electromagnetic energy too?

And, I think their disclaimer is already perpetuating the fear message.
 
A quick internet search shows that on average, there are only one or two unprovoked SCUBA diver shark attacks per decade, and that most divers actually like to see sharks, I find this device to be on-par with a "flavor remover" for steaks.

Since a diver is much, much more likely to die from stupidity than sharks, if you're going for safety, I'd rather see C-cards that require periodic renewal than a shark repellant that chases off stuff I want to see while at the same time not guaranteeing that it will actually stop the event it was designed for.

flots.
 
Thank you, for the facts. However my humble opinion is that facts alone are not going to cut it with the scuba community. I free dive with a Freedom 2 in False Bay South Africa, however if I boat dive or dive with a scuba schools in false bay I get a very frosty reception to my shark shield, so much so that I do not use it at all. The inference is we want to see sharks (I Don&#8217;t not a Great White at any case unless on my terms) or you are so unlikely to be attacked by a shark as to make it pointless! I would love to hear some other opinions from the scuba community. My free dive buddies would not be seen dead without their range of sharkshield products from freedom 2 to freedom 7&#8217;s.

I await some comments on this eagerly.

Hi Stephen,

I live in South Australia (SA). A key concern to those of us here in SA who go into the sea is the potential for in-water encounters with Great White Sharks. I am a scuba diver who is currently using my second Sharkshield product (i.e. a Freedom 7). While the product is widely used here by scuba divers, there are sceptics. The product appears to have some limitations as evident in the results of a recent SA government study whose report can be downloaded from a link on the following thread - http://www.scubaboard.com/forums/sh...ess-shark-shield-freedom-7-a.html#post6394300.

---------- Post added May 11th, 2013 at 03:51 PM ----------

A quick internet search shows that on average, there are only one or two unprovoked SCUBA diver shark attacks per decade, and that most divers actually like to see sharks, I find this device to be on-par with a "flavor remover" for steaks.

Since a diver is much, much more likely to die from stupidity than sharks, if you're going for safety, I'd rather see C-cards that require periodic renewal than a shark repellant that chases off stuff I want to see while at the same time not guaranteeing that it will actually stop the event it was designed for.

flots.

Hi flot am

The number of shark attacks in Australia since 2002 can be viewed with details of the events & in most cases, the names of the deceased - Shark attacks in Australia: Timeline - Australian Geographic. From the list, the following individuals were scuba diving - Peter Kurmann, George Thomas Wainwright, an abalone diver taken in 17 February 2011 (i.e. Peter Clarkson) and Jarrod Stehbens. The former two were diving in Western Australia (WA) and latter two were diving in South Australia (SA). There are at least two scuba diver fatalities caused by sharks in SA - single fatalities in 1986 and 1991.

While your average per decade appears to be about right, one's perspective changes when one personally knows either the fatality, his/her family or friends, or people present at the attack as I have discovered.

---------- Post added May 11th, 2013 at 03:52 PM ----------

I don't see this as a great thing for scuba. Unless there is an on off switch? Because I would think that the field would turn on quite quickly if one were to find themselves in an (unlikely) situation. .

Hi AaronRiot,

Both units that I have owned had on/off switches.

---------- Post added May 11th, 2013 at 04:00 PM ----------

I have seen this on boats from time to time and I have at least two questions: How does it affect other marine animals, especially at close range?
In fact, since I actively seek out sharks and rays to photograph them, will this inhibit that endeavor?

Hi NetDoc,

Firstly, I have noticed that the electric field does irritate some animals (i.e. crabs). Secondly, Sharkshields do not repel all sharks and rays - a dive buddy had a close encounter with a large 7 gill shark whose not affected by the shields worn by my buddy & those diving with him. Most of the relatively harmless (or almost harmless) sharks (including catsharks) appear to not affected by the field. The manufacturers' instruction indicates that the product is intended for predatory sharks whose snorts have Ampullae of Lorenzini.
 
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The device seems to work well in my experience. I have seen the effects of sharks being deterred from taking speared fish that are hanging below a diver. I also know that it has ZERO effect on nurse sharks.. with the electrodes being touched to the shark and no noticable response...
 
https://www.shearwater.com/products/perdix-ai/

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