The risk of a shark attack when diving inshore waters of Western Australia

[KevWind]

Good you have refrained from personal attack a start.
Although you have slipped in some all encompassing euphemisms ( greeny ideology) which perhaps in your mind indicates something negative or dismissive, but could in fact be interpreted as simply someone who actually cares about the natural order of the environment. And perhaps disagrees with your personal perspective in regards to "priorities" And of course your penchant for the euphemism "Man Eating" a statistical a misnomer.


Even with all that
You have in fact peripherally if unintentionally hit upon the fundamental difference of perspective that is underpinning this discussion.

I’ve previously highlighted the growing scepticism and frustration of people in Western Australia to the growing number of fatal shark attacks and the failure of the government and government agencies like Fisheries WA to deal with the problem.

Yes and presumably you align yourself with this perspective. Of course it would take less than a minute to google up links and highlight numerous instances protests and people in WA who disagree with you about culling efforts.
So can we say that beyond this board the same differences of perspective exist.

One of the big government initiative has been the ‘Shark Response Unit’ created within Fisheries WA. You can read the stated objectives of the unit and about its efforts in shark tagging and monitoring here:
Shark response unit

I’m not sure where their objectives came from

Seems pretty clear, the objective came from a desire to do "Do research and provide advice and information to members of the public that will assist them in making informed decisions when using the aquatic environment".

but it is obvious that the department’s basic philosophy is that protecting sharks is the priority and if a man eating shark is in the water people should stay out of the water or accept the risk of getting eaten.

what is unclear how you have reached this conclusion based on the stated Shark Response Unit objectives below ? But even so, you seem to think this priority of informing the public shark activity in specific locations. As opposed to questionable culling tactics , is somehow a negative or invalid philosophy. Yet many here and obviously in WA clearly think it is a perfectly valid philosophy. There in lies the fundamental difference



Shark response unitThe Shark Response Unit was created in early 2012 to conduct research into shark populations and movements, improveresponse plans and procedures, and provide advice and information to members of the public that will assist them in making informed decisions when using the aquatic environment.

The Unit has received $3.75m in funding over five years which includes $1.7m for four major research projects. We have also commissioned our patrol vessel Hamelin to the Unit to improve our capability to manage shark hazards and carry out important shark research and tagging activities along the WA coast.
We will work to highlight the importance of reporting shark sightings to the Water Police​ and the communication and response process that follows. The Unit will also investigate systems that alert beach goers and other users of the aquatic environment when shark sightings and incidents occur.
The Unit is also tasked with:

• Exploring the use of community-based programs that could contribute to public safety along our coast;
  
• Undertaking a desktop study to evaluate the effectiveness of shark deterrent or repellent devices in the marketplace; and
  
• Investigate the legislative and social implications and risks for any potential shark cage tourism.​

​​​​

I believe this approach is built on the greeny ideology that the ocean is the shark’s domain and you enter at your own risk. The government echoed these sentiments for a number of years up until recently.

Again just because it differs from your personal perspective does not invalidate it. And just because the government caved to outspoken public and possibly yet to be disclosed private interest pressure does nothing to validate the decision.

Colin Barnett came to understand the harsh reality of the greeny ideology he had quoted so glibly in the past and that protecting beach goers and human life was the priority.

Or he simply caved and decided to go with the strongest current political winds ( imagine a politician doing that !!!)

But it seems that the Fisheries WA scientists continue to cling stubbornly to this ideology

. Or decided not to cave to ill-advised witch hunt mentality.

Mr McAuley is paid by the public and holds his office primarily to serve the interests of the public. In this case public safety should be the priority. It is becoming increasingly apparent that culling white pointers is not a risk mitigating strategy that Mr McAuley and his department are prepared to consider

. Or it could be because "killing a few sharks" won't really mitigate anything particularly if indeed the numbers have "increased drastically". and refuses to perpetrate a sham that could end up giving the public a false sense of security. For which he should be given acclaim





I could go on questioning or refuting your conclusions or offering viable alternate conclusions. But I suspect because of the basic difference of perspective and priorities it would prove futile, so with that I leave you to your perspective . cheers

 

[live&dive]

Sounds like some people have a gross misunderstanding of how marine ecology works. Shark culling is a solution to a largely non existent problem. I suppose if we lived in water and we were constantly under attack in our homes by "man-eating sharks", there would be an issue. Reality is that the possibility of getting attacked by a shark (however, extremely slim) is inherent with being in the ocean. Drowning is still a far greater risk.

 

[drrich2]

I’ve previously highlighted the growing scepticism and frustration of people in Western Australia to the growing number of fatal shark attacks and the failure of the government and government agencies like Fisheries WA to deal with the problem.

Perhaps because at the national level it's not that significant a problem. Many things kill a lot more people than the sharks are.

You still haven't given any position on what # of people are deemed acceptable losses to have a healthy white shark population in the oceans. This is a difficult question but merits an answer. If the same # of people had been killed in recent years, but that # was a decline instead of an increase, you might be satisfied with it.

I see there have been fatal white pointer attacks in Southern California but then your population density is much higher than here. Over here I'd consider any encounter with a white pointer to be potentially fatal and to be avoided but then again it's the ones you don't see that are the problem.

An encounter with any animal capable of killing a human is 'potentially fatal' - a horse, dog, etc... Long ago sharks were viewed as non-discriminating generalists apt to eat anything they could when hungry; modern thinking is that no, whites aren't prone to attack humans on sight and rarely do.

For that matter, getting in the ocean is potentially fatal in & of itself, even if no sharks are present.

Mr McAuley is paid by the public and holds his office primarily to serve the interests of the public. In this case public safety should be the priority.

That's not an absolute, so it's not quite the compelling point you may think. Otherwise nations around the world would actively exterminate most any animal that we know will eventually kill some human somewhere. Including dog breeds large enough to kill, horses, elephants, lions, tigers and so forth. Having these species exist implies an obligate willingness to part with a few human lives.

The same applies to divers. In a recent case a dive instructor on a charter was ordered out of the water because a large white pointer had been seem in the area. The instructor eventually jumped back into the water and finished the course. A couple of the students had seen the white pointer come to within 15 m during the course. The warning system had worked as well as it could but divers' safety was still compromised.

A couple of points.

1.) The shark didn't attack anyone. The degree of 'safety compromise' is highly in question. They weren't safe to begin with; they could've drowned, been killed by something else, etc... The degree of added probability of serious injury or death brought on by a nearby white shark is probably quite small and perhaps for practical purposes negligible.

If these sharks were as dangerous and numerous as you seem to think, there ought to be a whole lot more attacks than what've been reported.

2.) The people, presumably adults, were warned about the shark, and made an informed decision to take on the risk. Therefore any 'nanny state' concern over their allegedly compromised safety is nullified. They were told, and they made their choice. Nobody died & likely the students got certified and the instructor got paid.

Richard.

 

[Ste Wart]

I just like to add there is no such thing as a man-eating shark. Sharks eat fish. Divers, snorkellers, free-divers, taken by sharks are incredibly unlucky, that is all. A shark does not actively seek out human flesh. It hasn't spent 400 million years evolving on the hope that some primate will go for a dip and it'll get lunch.

We do not have a right to decide which animals deserve to live in the ocean based on our values. Sharks are a part of the marine ecosystem, an incredibly important part. We do not have the right to cull sharks based on tourism. This isn't Jaws.

 

[Foxfish]

You still haven't given any position on what # of people are deemed acceptable losses to have a healthy white shark population in the oceans. This is a difficult question but merits an answer. If the same # of people had been killed in recent years, but that # was a decline instead of an increase, you might be satisfied with it.

I'd consider a return to fatal shark attacks levels that existed for say seventy years prior to white pointers becoming protected to be acceptable. My reading of the Shark Attack File records is that there were only two cases where people clearly attacked and killed by sharks during that period. One was in 1995 and the other in 1967.

I don't see why diving agencies should treat the risk of an injury or fatality from any marine animal including sharks differently from any other risk faced by a diver. The only discussion I heard about the risk of a fatal shark attack on the courses I've done was people playing down the risk.

In fact I was barred from a wreck dive while doing my advanced open water course because I insisted on wearing a Sharkshield in an area not far from a recent fatal attack on a snorkeler. The instructor cited concerns about the risk of entanglement while diving the wreck as the reason for barring me from the dive. I had offered to take the Sharkshield off prior to entering the wreck. I've subsequently done the dive on several occasions with the Sharkshield on and never had a the slightest problem. I find it ironic the instructor was absorbed with the risk of entanglement which while completely ignoring the more significant risk of shark attack. I attribute that mostly to a failure in his training as a diver and instructor.

I view this as a more general problem of diver/instructor training. It is a failure of divers to properly assess the risks associated with actual conditions in which they dive. Diver training tends courses are developed assuming a certain diving environment. Aspects of that environment are sometimes clearly defined (eg. depth limitations), sometimes it remains unspoken. It's easy for trained divers to dive according to risks assumed in the course book rather than real world risks. The experience I related above being a case in point.

A couple of points.

1.) The shark didn't attack anyone. The degree of 'safety compromise' is highly in question. They weren't safe to begin with; they could've drowned, been killed by something else, etc... The degree of added probability of serious injury or death brought on by a nearby white shark is probably quite small and perhaps for practical purposes negligible.

If these sharks were as dangerous and numerous as you seem to think, there ought to be a whole lot more attacks than what've been reported.

But what if I now changed the scenario. Suppose the shark then went and killed a young girl soon after the initial attack? This is no idle tale. I vividly recall after one fatal attack that the authorities spent several days looking for the victims body.

The attack was witnessed and the body was never recovered. In the mean time a four metre white pointer, the same size as the one that attacked the victim, continued to swim around the area and menace other water users.

Couple describe close encounter with great white shark

This shark should have been destroyed without a second thought.

2.) The people, presumably adults, were warned about the shark, and made an informed decision to take on the risk. Therefore any 'nanny state' concern over their allegedly compromised safety is nullified. They were told, and they made their choice. Nobody died & likely the students got certified and the instructor got paid. Richard.

On this occasion, yes. Ironically the instructor and students were from a dive shop that had recently been interviewed by the media.

Managing director Lee Johnson said the industry was leading the way helping to educate people about sharks - a position he urged the Government to adopt instead of killing them.

"Yes, there are sharks in the ocean and there is a very small risk, but your chances of even seeing one are just so low compared with the health and well-being benefits of enjoying a day in the water," he said.

Sharks don t deter divers - The West Australian

You don't need to look far to find examples of people in the industry playing down the risk an attack - for obvious reasons. Somehow it is acceptable until someone gets hurt.

 

[drrich2]

Thanks for clarifying what you deem acceptable fatality rates. While any such figure from any of us is apt to be a bit arbitrary, at least it provides an idea what you're shooting for.

I don't see why diving agencies should treat the risk of an injury or fatality from any marine animal including sharks differently from any other risk faced by a diver.

They don't always. But there is a different issue. I'll come at this from 2 directions, using as a comparitor the argument a few have made on this forum that divers ought to routinely test (and carry analyzers to test) regular air tanks for carbon monoxide, as on rare occasion high levels in scuba tanks can imperil human life.

1.) I don't remember my OW manual covering this. That was back in late '05, granted, and I certified in early '06, but still, I don't think the issue was brought up. So not all very low risks are covered in diver education.

2.) Efforts to alert the public about, investigate for causative system deficiencies contributing to, and modifying systems and regulations to address equipment failure issues (e.g.: exploding tanks, carbon monoxide in tanks, etc...) are highly unlikely to lead to interventions that may drive a species closer to endangered status.

So if you told me that for that same time period 8 dive shop staff were killed by 8 separate exploding scuba tanks getting filled, and there were people who suspected a manufacturing process contributed to a defective alloy and this issue could be corrected in a practical and cost effect manner, yes, I think many of us would approve.

Yet going out on a mission to kill a bunch of great whites over 3 meters long will be viewed differently.

But what if I now changed the scenario. Suppose the shark then went and killed a young girl soon after he initial attack?

It would be much as what happens when we hear that an OW course student drowned during one of the required OW dives. We lament the loss, sympathize with the family, some may pray for the soul in God's hands, but most of us don't conclude that diving is too risky due to the risk of drowning.

You don't need to look far to find examples of people in the industry playing down the risk an attack - for obvious reasons. Somehow it is acceptable until someone gets hurt.

The issue of shark attack is so psychologically charged that it's hard to have a truly objective discussion from either side. The public is prone to sensationalizing and irrationally exaggerated fear of shark attack, when compared to things they hardly bat an eye brow at that are far higher risk to kill them. Knowing public ignorance and volatility are a bomb waiting to go off, people who care about shark conservation are sometimes apt to try to allay public fears.

I don't think any of us wish to downplay the horrific trauma of being mauled by a monster shark with a gaping maw lined with rows of serrated up to 2 inch teeth and enormous bite force, possibly shearing a leg off at the knee the victim thrashes and screams, inhaling water, etc... But then than, not all great white attacks are like that. The 2010-2014 (thus far) data you posted for us indicates that 2/3'rds of the attacks for that time period weren't even fatal. That still leaves room for awful injuries, of course.

But it's like the man-eating tiger that's killed somewhere around 10 people. Reading about the deaths sounds mighty gory. But conservationalists will try to emphasize that this animal is a rare exception that does not justify exterminating tigers.

One key difference; with 'man-eating' big cats, sometimes you get a feline 'serial killer.' As with the tiger killing in India now. I don't believe I've heard of a real life great white doing such a thing.

Richard.

 

[PeterNBiddle]

There are 10 Ozzies killed per year by honey bees - 5 times as many as are killed by sharks.

Do you wear a special bee-guard suit when you walk around flowers?

There simply isn't a problem here that needs to be solved.

http://www.bobinoz.com/migration-advice/australias-killer-creatures-the-truth-about-deaths/

 

[Foxfish]

There are 10 Ozzies killed per year by honey bees - 5 times as many as are killed by sharks.

Do you wear a special bee-guard suit when you walk around flowers?

There simply isn't a problem here that needs to be solved.

Australia?s Dangerous Animals: The Truth About Deaths.

Interesting perspective on the topic, but the number of deaths alone don't give the whole picture. You would need to also assess the hours of exposure to a risk and determine a probability of something happening taking this into consideration.

Another way to consider the risk would be the following mind game. Imagine you are in the middle of a fenced circular bare paddock. It is getting dark and you can only see for a distance of 20 m. The paddock is 4 km in diameter. There is a wild beast roaming the area that can move at *56 km/hr in a short burst (1). You speed is restricted to a walking pace*. Even in the dark the animal can identify your presence from 1.5 km (3) and can sense your movements and direction of travel from 250 m (2). The animal is considered very aggressive towards humans and is known to cut them in half with a single powerful bite.

How safe would you feel in that situation? What would you consider to be the risk of a fatal attack in that situation?

1. A white pointer can swim at speeds of up to 56 km/hr. http://en.wikipedia.org/wiki/Great_white_shark I'd estimate a fast swim in scuba gear would be 60 m in a minute which is 3.6 km/hr. That means a white pointer can swim about 16 times as fast as a human in a short burst.

2. Great white sharks have an elaborate sense of touch through what’s called the lateral line – a line that extends along the middle of the shark’s body from its tail to its head. This line, which is found in all fish, is made of cells that can perceive vibrations in the water. Sharks can detect both the direction and amount of movement made by prey, even from as far as 820 feet (250 meters) away.

http://ocean.si.edu/great-white-shark

3. A shark is equipped with an extraordinary array of sensors, probably the most diverse of any known predator. Low-frequency sounds tend to travel great distances underwater, so a shark's auditory system could be the first sense to pick up an interesting target. Rapid, irregularly-pulsed, broad-band sounds at frequencies below 600 hertz, similar to those made by injured prey or a group of spawning fish can alert a hunter such as a bull shark from over 1.6 km (1 mile) away.

At a distance of 0.5 km (1/3 mile), it is able to smell blood in the water and follow a trail back to the source. It can detect one part of fish extract in 25 million parts of seawater, the equivalent of ten drops of blood in an average-sized municipal swimming pool. At 100 m (330 ft), the shark's lateral line system kicks in. This row of fluid-filled sensory canals on either side of its body responds to pressure changes and movements, so a shark can almost feel the presence and location of something moving in the water--a kind of 'touch-at-a-distance.'

http://www.nhm.ac.uk/print-version/...phibians-fish/sharks-jaws/session2/index.html

 

[Foxtrot16]

I’ve previously highlighted the growing scepticism and frustration of people in Western Australia to the growing number of fatal shark attacks and the failure of the government and government agencies like Fisheries WA to deal with the problem.

Not me and not everyone in WA is frustrated so please don't speak for all of us.

I dive every weekend in the waters of Perth especially around Cockburn Sound and I have never seen a shark a part from the odd baby Port Jackson or the dead ones killed by the redneck fools at the Ammo Jetty.

If you are worried about sharks then don't go diving in the ocean - stick to a few of the inland lakes and dams - but wait a yabby or marron might get you.

 

[Foxfish]

Not me and not everyone in WA is frustrated so please don't speak for all of us.

I dive every weekend in the waters of Perth especially around Cockburn Sound and I have never seen a shark a part from the odd baby Port Jackson or the dead ones killed by the redneck fools at the Ammo Jetty.

If you are worried about sharks then don't go diving in the ocean - stick to a few of the inland lakes and dams - but wait a yabby or marron might get you.

Where are you diving around Cockburn? Try the D9 September to November for a bit more action. I hear night diving is good for white pointers.

No one said I was speaking for everyone but you'd have to have your head buried in the sand not to have noticed the rising level of concern regarding the number of shark attacks in recent years.

Oh and I don't believe anyone who says they dive every weekend in Perth - unless they go down to a pool.