Shark Repellent Responses New Zealand, Scotland, South Africa, and Spain
New Zealand
Regarding sharks. I have never really considered using a repellant due to the fact that attacks here in Aotearoa are uncommon. In saying that, I am very aware that when I am shooting at dusk or dawn (when the light is optimal for creating images) and especially when I am shooting flash images in the water, there is always a chance that I will have an encounter with a shark. I guess I try to put it out of my mind and focus on enjoying being in the ocean and doing what I'm doing. The ocean is a shark’s home; it's their environment and we are guests. I met a guy who worked for Sharkdiver Magazine and was shooting a feature on sharks at the bottom of the South Island for the Discovery Channel a few years back. You get some enormous Great Whites down in those waters and the interactions he is able to have with them blew my mind. I guess if a repellant was proven to minimize the risk of an attack while not harming the creature I would be all for it. Overfishing appears to be having the biggest impact on where sharks are looking for food, so I think getting this under control would be the optimal means of limiting future attacks.
Jim Culley
Photographer
Response
This discussion is timely given the recent attention shark populations are receiving from both shark attacks and increasing regulations on the shark fin trade. While even the most skilled water person is not immune to the power of the ocean, I find the risk to be part of the allure. As a surfer, the idea of shark deterrent technology is compelling; and as a mother, I would likely encourage my children to use shark deterrent technology that has been shown to decrease the risk of an unwanted shark encounter. However, as a conservationist, I question the ethics of invasive technologies, such as shark nets or electric fences. Among others, this paper discusses the use of shark tags as triggers for an electric fence-type technology. Instead of “zapping” sharks, I would like to see this or similar technology used to improve more passive measures designed to reduce encounters between sharks and ocean users (e.g., shark spotting technologies).
Dr. Brooke Porter
New Zealand Tourism Research Institute
Auckland University of Technology, New Zealand
Scotland
My comments come from research on sharks and from being an avid diver having spent a lot of time underwater with a wide range of species. The problem with the majority of shark repellents is that they come with the manufacturers claims of working, but they have not been rigorously tested and published through peer-review. That is starting to change but it’s important to stress how difficult it will be to test repellents under the scenarios by which a shark may attack a human. For example, attracting sharks with bait while testing may still not elicit the same response as an animal that is naturally trying to forage on large prey on the surface. My own personal experience has been using a shark shield with bait experiments in Hawaii, which I was not impressed with. Other methods such as electric / magnetic / chemical / visual repellents may work in some situations but their effectiveness in other locations/situations are less clear.
There are some methods currently being tested that show promise, but I certainly would not bet my life on them working and have not seen nearly enough to say that they will work. I would personally not bother using any devices currently on the market, at least when it comes to diving.
Dr Yannis P. Papastamatiou
Scottish Oceans Institute
University of St Andrews
South Africa
Having worked on this issue for 17 years and having dealt with 18 shark attacks below are the key points that I have learned:
1) It is the fear of shark attacks as opposed to the actual risk of shark attack that is a major factor. That fear can have a major and substantial impact on how people perceive and use the ocean. The real risk of shark attack is extraordinarily low, but human emotion is a powerful driver of fear and in short “emotions trump statistics when it comes to sharks”
2) Appropriate shark safety measures are important for people but are as important for sharks as part of an overall shark conservation and protection strategy
3) I don’t believe any deterrents at this stage are far enough developed or tested to be viable options. Here in Cape Town our Shark Spotting programme has worked very well and is the approach we advocate
4) It will never be possible to tag every great white and the cost of even trying will be excessive. In addition you would need to re-tag on a regular basis as batteries run out and tags fall off. Tagging itself can at times be quite damaging to the sharks
5) In Cape Town we are opposed to any safety measures that cause harm or kill sharks or reduce the population
6) Electronic barriers as being tested by the KwaZulu Natal Sharks Board at the moment hold much promise but are yet to be developed far enough to be used. In addition the financial cost of running such systems may make them unusable. Only time will tell
Gregg Oelofse
Response
In my experience, a shark safety system, particularly in areas of high overlap between sharks and people is needed to keep people safer, but is just as important for shark conservation.
Most shark deterrents have not been rigorously tested, and those that have been e.g. Shark Shield, are not 100% effective. However, these tested electric deterrents can provide a degree of extra safety in some cases and are therefore a viable option for water users - as long as the wearer is aware of the limitations.
When it comes to keeping people safer from sharks, it is important to remember that ‘one size does not fit all’ – each area needs a tailor made shark safety system. In some cases this may simply be a focus on awareness of high risk areas and times of encountering sharks, in other cases additional options could be available. In Cape Town, we have a large aggregation of white sharks living next to a major City and we have used a combination of methods to keep people safer. We provide an early detection and warning system in the form of dedicated Shark Spotters at 8 beaches, and we use an environmentally safe shark exclusion net at a single beach. The Shark Spotters programme itself has proven to be effective at reducing overlap between people and sharks, but is not 100% effective due to not being able to spot sharks in all conditions, all of the time. On the other hand, shark exclusion nets provide 100% safety from sharks because they form a barrier between people and sharks, but they are limited to relatively protected bays. We also use the knowledge gained through applied research to advise people on high risk areas, times of year and certain local conditions. Education and awareness are an important part of the system with informative signage at all beaches, high risk signage at certain beaches, an information centre on one of Cape Town's most popular beaches and accessibility to a network of recent and confirmed shark sightings through various social media channels. Temporary beach closures are also used when there is unusually high shark activity in the area.
Detection and warning methods coupled with a response system, in my view holds the most promise in terms of practical application, low cost and use over larger scales. This is especially true for surfers that use surf zones where exclusion nets are not viable, or electric barriers which may also be a challenge to implement in surf zones or cover large areas. Trying to influence shark behaviour by deterring different
species under all conditions has proven to be a major obstacle in the advancement of deterrents. While the Shark Spotting programme is not viable in all areas due to lack of elevation for human spotters or inconspicuous shark species, the concept of an early detection system combined with a response to temporarily get people out of the water, is replicable. Advances in technology, such as high definition cameras (possibly fixed on high structures overlooking beaches or surf breaks) or underwater sonar, might provide more high tech detection capabilities and should be investigated as viable options.
Dr. Alison Kock
Research Manager
Shark Spotters
In the field of personal shark repellents, the KZNSB during the 1990s developed and marketed the first successful electrical personal shark repellent unit called the POD™. In the mid-1990s this technology was licensed to SeaChange™ Australia now called Shark Shield™. The original shark repellent technology used in the POD is currently being used in the personal shark repellent units called Shark Shields which are freely available in the market.
Whilst it has been statistically proved that this technology as incorporated into the Shark Shield does have a repelling effect on sharks it nevertheless is incumbent upon all entering any marine environment to exercise due diligence, caution and be aware of potential threats as may be caused by sharks encountered. In many cases it really comes down to basic common sense and taking the time to familiarise oneself with any and all potential hazards.
The KZNSB has an ongoing program for the development of an Electrical Shark Repellent Area Barrier which could be used at bathing beaches, surf spots and the likes. Sea trials were conducted over a 6 month period this year past in False Bay, Cape Town. Even though the system proved sea worthy and performed as per specification from an engineering and design performance perspective, the lack of white shark interactions with the Area Barrier during the test period prevented the collection of the required animal avoidance validation data. The KZNSB is pursuing this research and we expect to continue field trials during the latter part of this year in this regard.
I am of the opinion that it may not be a single technology that provides the answer to the problem faced but that it may well end up being a combination of various technologies that provide the answer.
Much has and continues to be emphasized about the disproportionate reaction and actions taken in view of the recent sharks attacks worldwide. The fact remains that shark attacks will continue and public education alone will not prevent all shark attacks. If different technologies can provide the answer to this problem without having any negative impact on the environment then surely we must peruse this research. Man walked on the moon over 46 years ago and as I write this email the Rover continues to drive on the surface of Mars, surely we can and must do better when it comes to the question of technology, sharks and man.
The KZNSB remains committed in its search for better methods of protecting both sharks and sea users.
Paul von Blerk
Response
Excuse the brevity of this response. I recently attended the 3rd Southern African Sharks and Ray Symposium (SASRS) where shark repellents were discussed. Quite simply, I have come to believe that shark repellents can be a powerful tool of ensuring the safety of both ocean aficionados and sharks, although the proposition receives vocal dissent from shark scientists that emphasize the lack of adequate
knowledge on behavior (that of both sharks and humans). Of course, for any rigorous scientific approach, the proof of the pudding is in the eating, in other words the results of shark repellent studies should wherever possible be validated by independent data. Shark repellents are better than “culling devices” that intend to minimize shark-human encounters through death of an animal in its natural environment, at least in my view.
Simo N. Maduna, M.Sc. cum laude
Ph.D. candidate
Department of Genetics
Stellenbosch University
Spain
I fully agree with Lindy Weilgart and Sebastian Biton Porsmoguer. Any system that uses electromagnetic radiation to scare away sharks particularly affect species with low mobility who live in the area (bivalves, algae, corals, small fishes, crabs ...) and affect much less to highly mobile species who often travel long distances and spend little time in the same place (like sharks…), because the effects of these radiations normally are long- term and the exposure time is an important variable to consider.
Alfonso Balmori
Biologist, Spain