So You Want To Buy A Personal Shark Deterrent?
Personal Shark Deterrent Technologies – what’s out there and do they work?
Story By Dr. Niuhi, Marine Scientist, Diver & Surfer
Demand for shark deterrent technologies has surged over the past decade with anti-shark technologies flying off the shelves for use by divers, surfers, kayakers and the like, due to the increasing amount of shark-related incidents and reports being streamed by the media nationwide. The Shark Summit in Sydney last week listed a number of the personal protective measures that are available so we’ve delved deeper into each to help you understand what they do whether they are effective.
Let’s talk numbers. According to the Taronga Conservation Society, Australian Shark Attack File, there have been 1003 shark attacks in Australia since 1791, of which 232 were fatal. 27 of them have occurred in the past 15 years with 11 in WA, 6 in NSW, 5 in SA, 4 in QLD and 1 in Tasmania. Whilst this number may appear frightening, it’s a minuscule contributing factor to total deaths in Australia.
Of the 180 species of sharks in Australia, which ones are the culprits? You probably wouldn’t be surprised to learn that it comes down to a small number of species responsible for fatalities and unprovoked attacks around Australia - white sharks, tiger sharks and bull sharks. The common denominator between these three is they are all equipped with serrated teeth enabling them to wear the badge of ‘iconic top predators’.
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Let’s talk species. There are a couple of crucial things to note in regards to these species which will help you understand why these sharks are getting all the attention. White sharks (i.e great whites) mainly prey upon marine mammals such a pinnipeds (seals) and toothed whales and sea turtles. Whites tend to investigate their prey through a surprise attack and often from below, and release prey that is unpalatable; therefore a white shark attack is not always fatal resulting in 30% of unprovoked white attacks ending in death. Tiger sharks are next in line, with 40% of unprovoked attacks ending in fatality. Tigers will eat just about anything; I often refer to them as the turtle can-opener of the tropics. Their prey includes sea turtles, fish, sea birds, cetaceans, squid and crustaceans – a much more diverse array of prey species.
Last but not least, the Bull shark. Bull sharks prefer shallow murky waters which is a perfect recipe for an attack as bull sharks often exist where humans love to recreate, in particular river mouths due to their ability to adapt their osmoregulatory processes to survive a broad range or water salinities from salt to freshwater. Bull sharks prefer bony fish, sharks, rays, crustaceans, sea turtles, small cetaceans such as dolphins and squid on their dinner plate.
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The commonly believed notion that bull sharks have the most testosterone of any animals on the planet is also lacking evidence. From the limited research available it appears that bull sharks aren’t always the roided sharks that some folks might have you believe, in fact, the notion that they are is based on one, very impressive, male bull shark that was caught in the wild exhibiting testosterone levels roughly 9 times that of other sharks (358 ng/ml), however, other male bull sharks sampled exhibited levels less than sharks regarded to be fairly tame (sandbar and bonnethead sharks), in fact one hundred fold lower than its roided counterpart. That said, testosterone levels exhibited across a range of species are higher than terrestrial species such as the male elephant (whom leading up to the mating season exhibits an average of 64 ng/ml). So whether testosterone levels are responsible for the bull shark’s place in the top three shark species responsible for human attacks is still to be determined. The jury is still out, no bull!
Humans are not on the chosen dinner menu of any of these sharks and are most likely a case of mistaken identity where between 30-40% of unprovoked attacks end in fatality. Put plainly, they possess the machinery but lack the motivation. On the flip side, if you’re out there provoking sharks, then you’re likely to come off second best and you could probably do with a lobotomy.
Never the less! – if you are someone that frequents areas where these sharks inhabit then a little bit of peace of mind can go a long way for you and your family and help you to enjoy your recreational water pursuits.
So what’s out there? Shark deterrent technology has come a long way over the last 10 years and is available in a variety of forms from shark shields of all sizes and applications to wetsuit and surfboard visual technologies. Here’s what’s out there and how it’s meant to work…
Shark shields have come a long way since the cumbersome devices of the 90s when it first discovered that sharks have a heightened sensitivity to close-range, low-frequency electrical fields. Two decades of global research has helped to develop them into an efficient compact module that you can buy off the shelf today.
Shark shields consist of two electrodes which when both are submerged emit a three-dimensional electronic field that surrounds the user. When a shark comes to within a few meters of the Shark Shield, the strong electronic pulses emitted by the device cause the shark to experience muscle spasms and a high level of discomfort. The closer the shark is to the Shark Shield field, the more spasms occur in the sharks’ snouts, which results in it turning away from the electronic field, thereby protecting the user.
These devices attract good solid reviews from free-divers to surfers, most of which noting that when in a group of divers, those that wore the shield had far fewer and encounters than those that did not.
Retail: starting at $649 AUD
- Good reviews
- Battery lasts up to 7 hours
- Multiple uses (kayaking, SuPing, Diving, surfing)
- The product has been around a long time which to a degree speaks for itself
- The shark shield has been known to interfere with some dive computers
- It is designed to work in seawater only as freshwater has a reduced ability to conduct electrical energy
- Can cause a slight electric shock if the antenna is accidently touched when submerged
- Anyone with heart conditions of any description, epilepsy, and blood pressure issues are advised to seek medical advice before use. People who have pacemakers or are pregnant must not use the Shark Shield and should also avoid swimming near any other person using the Shark Shield.
Shark deterrent technology specifically for surfers: This relatively new lightweight device is integrated into your board and not an external attachment, thus presenting a very attractive option to the keen surfer. SURFSAFE’s shark deterrent technology, like the Shark Shield automatically activities when the two electrodes become immersed in salt water. The device needs to be custom fitted to your board, and once in, is good for three years.
Retail: $389 AUD
- The only way to get a shock for the device is to place your hands near both the electrodes whilst they are submerged or wet
- 12-hour battery life - Three-year lifetime
- Designed to be installed in a custom board but can be retro fitted but not an easy task and SURFSAFE recommends an authorised installer to undertake the work
- Anyone with heart conditions of any description, epilepsy, and blood pressure issues are advised to seek medical advice before use. People who have pacemakers or are pregnant must not use the Shark Shield and should also avoid swimming near any other person using the Shark Shield
- Yet to be around long enough to test effectiveness
Shark Deterrent Radiator Wetsuits
Western Australian based company Radiator Wetsuits, has launched a new range of wetsuit designs which utilise breakthrough science on shark sensory systems to develop combinations of colours and shapes to reduce the risk of shark attack. The new wetsuit designs utilise “SAMS” (Shark Attack Mitigation Systems) patented technology which has recently been developed based on collaborative research conducted with the University of Western Australia’s Oceans Institute and School of Animal Biology.
The research took the complex neuroecology of predatory sharks and translated it into specific designs that disrupt the visual perception of sharks. They’ve come up with two designs: ‘Elude’ designed for the wearer to blend with background colours in the water making it difficult for a predatory shark to detect or focus, mainly suited to the scuba or free diver. The second “Diverter” design makes the user appear highly visible while using disruptive colour patterns totally unlike any normal prey. The Warning Surfer’ design integrates with a patterned surfboard design to render a full visual from below when the surfer is paddling or stationary.
SAMS Technology applies newly discovered scientific principles of shark vision to the development of marine materials configured with specific patterns of colour, contrast, size and shape to present the wearer or object as either cryptic (disruptively coloured) or conspicuous in the ocean. The principles are based on the physiology of what predatory sharks can see at different depths, from various angles, in different light conditions, and times of the day.
I’ve been wearing the deep “elude” wetsuit for a year now when diving and spearing and have noticed a difference. Not only are these wetsuits comfortable (which you’d expect from a $500 price tag), but they go the mile in my books.
Retail: $500 AUD
- Radiator suits do not use any chemicals, electricity or magnets
- As it does not send out a signal of such it does not directly interfere with sharks sensory systems, it is purely a visual deterrent
- Not only are you investing in shark deterring technology, you get a well-made high-quality wetsuit too that can be tailor-made to your measurements.
- Initial tests have been completed in live conditions off the coast of Western Australia, on the SAMS technology. Whilst the initial trials were strongly supportive of the scientific principles, they are not 100% conclusive, and further testing is under way. Time will tell.
- The technology is designed around conditions of clear water and good light. In conditions where light has been reduced or water is murky protection will be reduced. At this stage that cannot be quantified exactly and will be subject to further field testing.
A substance developed in America that uses a natural chemical found in putrefied shark tissue that affects the smell and taste senses of a wide variety of shark species. Sharktec states “once our product is released into the water, a flight reaction is triggered in sharks that can clear a quarter mile safe zone for 30-45 minutes depending on currents and wind”. The product is designed to hinder a sharks hunting ability through impeding its sense of smell and thus disrupting its sensory system. Unfortunately there haven’t been too many reviews posted to know if the product lives up to its claims.
Retail: $29.99 USD
- Spray form, this could be a pro or a con depending on personal choice
- Low cost
- 100% natural and biodegradable
- Depth rating of up to 13m
- Only ejects for 60 seconds and lasts 30-45 minutes
Sharkbanz enlisted the services of renowned shark experts, chemist Dr. Eric Stroud and marine biologist Dr. Patrick Rice to assist in the development of magnetic shark repellent technology. The two scientists founded Shark Defense almost 15 years ago, and are now the leading researchers in shark repellent technology. As the shark approaches a person wearing Sharkbanz, magnetic waves coming from the band disrupt its electro-receptors causing it to turn away quickly, “like a person suddenly shining a very bright light in your eyes in a dark room, and it's not pleasant”, according to Dr. Stroud. Once a shark comes near the band, it frequently leaves the area and does not return.
The effect of Sharkbanz is amplified if many people in a group of swimmers or surfers are wearing them. The device has been tested extensively on over ten of the most common predatory shark species such as the bull and black tips responsible for many close encounters; however it has not been tested on white sharks. Sharkbanz state “Great Whites are unique in that they are the only shark that acts as an ambush predator, attacking from a long distance at high speed. There is no effective way to prevent this type of ambush attack. However, Great Whites rely heavily on their electromagnetic sense when swimming in open water, and Sharkbanz could effectively deter an investigating Great White”.
Retail: $109.95 AUD
- Sharkbanz does not use any chemicals, batteries or electricity so there’s no risk of getting zapped
- Rated to 200m
- Kids can wear them
- Sharkbanz will reduce risk of shark interactions but there is no 100% guarantee that interactions will not take place
- Hasn’t been tested on white sharks
- Relatively new to the market and not extensively reviewed
Sharks can be dangerous and unpredictable creatures. The takeaway message is that there’s no concrete scientific consensus on what, exactly, will deter sharks and therefore, no device will guarantee that 100% of sharks will be deterred under all circumstances. The research however is convincing and several of the above products seem to be on the right track with testing supporting the deterrent technology.
We as individuals take a calculated risk whenever we enter the ocean, but the risk in quite small when compared to other daily activities like swimming, driving, and natural disasters all causing a much higher number of fatalities than shark encounters. The WA Department of Fisheries recently released a report on how to reduce your personal risk of interacting with a shark:
- Stay out of the water if sharks have been sighted in the area.
- Stay close to shore (within 30m of the water’s edge).
- Don’t go in the water alone (stay in groups).
- Avoid water temperatures lower than 22C.
- Avoid water depths of greater than 5m when swimming or surfing.
- Avoid swimming after heavy storms, or in low light conditions (dusk and dawn)
- Avoid swimming if there are seals, dolphins, whales or baitfish nearby.
Other tips include
- Don’t swim in murky water
- When spearfishing, keep your catch away from
- your body. Use a long tethering line or get your catch back in the boat quickly.
- Listen to your gut, be aware of your surroundings, if you feel uncomfortable, get out of the water. Never ignore your own internal early warning system!
- If you see a shark in the water, and are able to exit the water, stay calm and do so.
- Be cautious around juveniles, as they may be more curious and less laid back than adults.
- If you are diving and encounter sharks, watch for aggressive behaviour seen through side to side darting motion, elongated pectoral fins and an arched back. If you see this behaviour, the shark is agitated and there is a heightened risk of an encounter, stop what you’re doing and remove yourself from the area.
Rasmussen, L., & Murru, F. (1992). Long-term studies of Serum Concentrations of reproductively related Steriod Hormones in individual captive Carcharhinids Marine and Freshwater Research, 43 (1) DOI: 10.1071/MF9920273
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